Ceci est une ancienne révision du document !
Table des matières
Version : 2024.01
Dernière mise-à-jour : 2024/09/29 12:36
RH12413 - Gestion du Réseau
Contenu du Module
- RH12413 - Gestion du Réseau
- Contenu du Module
- Présentation
- La Commande nmcli
- LAB #1 - Configuration du Réseau
- 1.1 - Connections et Profils
- 1.2 - Résolution des Noms
- 1.3 - Ajouter une Deuxième Adresse IP à un Profil
- 1.4 - La Commande hostname
- 1.5 - La Commande ip
- 1.6 - Activer/Désactiver une Interface Manuellement
- 1.7 - Routage Statique
- La commande ip
- Activer/désactiver le routage sur le serveur
- LAB #2 - Diagnostique du Réseau
- 2.1 - ping
- 2.2 - netstat -i
- 2.3 - traceroute
- LAB #3 - Connexions à Distance
- 3.1 - Telnet
- 3.2 - wget
- 3.3 - ftp
- 3.4 - SSH
- Présentation
- SSH-1
- SSH-2
- Authentification par mot de passe
- Authentification par clef asymétrique
- Configuration du Serveur
- Configuration du Client
- Tunnels SSH
- 3.5 - SCP
- Présentation
- Utilisation
- 3.6 - Mise en Place des Clefs Asymétriques
Présentation
RHEL/CentOS 8 utilise Network Manager pour gérer le réseau. Network Manager est composé de deux éléments :
- un service qui gère les connexions réseaux et rapporte leurs états,
- des front-ends qui passent par un API de configuration du service.
Important : Notez qu'avec cette version de NetworkManager, IPv6 est activée par défaut.
Le service NetworkManager doit toujours être lancé :
[root@redhat9 ~]# systemctl status NetworkManager.service
● NetworkManager.service - Network Manager
Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled; preset: enabled)
Active: active (running) since Sat 2024-09-28 15:37:17 CEST; 20h ago
Docs: man:NetworkManager(8)
Main PID: 857 (NetworkManager)
Tasks: 3 (limit: 48800)
Memory: 12.0M
CPU: 1.834s
CGroup: /system.slice/NetworkManager.service
└─857 /usr/sbin/NetworkManager --no-daemon
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.6471] device (ens18): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.6481] policy: set 'ens18' (ens18) as default for IPv4 routing and DNS
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7310] device (ens18): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7327] device (ens18): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7328] device (ens18): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7331] manager: NetworkManager state is now CONNECTED_SITE
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7333] device (ens18): Activation: successful, device activated.
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7338] manager: NetworkManager state is now CONNECTED_GLOBAL
Sep 28 15:37:18 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530638.7340] manager: startup complete
Sep 28 15:37:29 redhat9.ittraining.loc NetworkManager[857]: <info> [1727530649.0717] agent-manager: agent[3c1f9786a5e709c2,:1.25/org.gnome.Shell.NetworkAgent/42]: agent registered
La Commande nmcli
La commande nmcli (Network Manager Command Line Interface) est utilisée pour configurer NetworkManager.
Les options et les sous-commandes peuvent être consultées en utilisant les commandes suivantes :
[root@redhat9 ~]# nmcli help
Usage: nmcli [OPTIONS] OBJECT { COMMAND | help }
OPTIONS
-a, --ask ask for missing parameters
-c, --colors auto|yes|no whether to use colors in output
-e, --escape yes|no escape columns separators in values
-f, --fields <field,...>|all|common specify fields to output
-g, --get-values <field,...>|all|common shortcut for -m tabular -t -f
-h, --help print this help
-m, --mode tabular|multiline output mode
-o, --overview overview mode
-p, --pretty pretty output
-s, --show-secrets allow displaying passwords
-t, --terse terse output
-v, --version show program version
-w, --wait <seconds> set timeout waiting for finishing operations
OBJECT
g[eneral] NetworkManager's general status and operations
n[etworking] overall networking control
r[adio] NetworkManager radio switches
c[onnection] NetworkManager's connections
d[evice] devices managed by NetworkManager
a[gent] NetworkManager secret agent or polkit agent
m[onitor] monitor NetworkManager changes
LAB #1 - Configuration du Réseau
1.1 - Connections et Profils
NetworkManager inclus la notion de connections ou profils permettant des configurations différentes en fonction de la localisation. Pour voir les connections actuelles, utilisez la commande nmcli c avec la sous-commande show :
[root@redhat9 ~]# nmcli c show NAME UUID TYPE DEVICE ens18 ea4c8254-6236-3130-8323-8b3f71d807a1 ethernet ens18 lo 8df82174-1d45-4506-9248-6bfcd2d20240 loopback lo
Créez donc un profil IP fixe rattaché au périphérique ens18 :
[root@redhat9 ~]# nmcli connection add con-name ip_fixe ifname ens18 type ethernet ip4 10.0.2.102/24 gw4 10.0.2.1 Connection 'ip_fixe' (b3d51921-4deb-4975-ad52-f31993b2af0c) successfully added.
Constatez sa présence :
[root@redhat9 ~]# nmcli c show NAME UUID TYPE DEVICE ens18 ea4c8254-6236-3130-8323-8b3f71d807a1 ethernet ens18 lo 8df82174-1d45-4506-9248-6bfcd2d20240 loopback lo ip_fixe b3d51921-4deb-4975-ad52-f31993b2af0c ethernet --
Notez que la sortie n'indique pas que le profil ip_fixe soit associé au periphérique ens18 car le profil ip_fixe n'est pas activé :
[root@redhat9 ~]# nmcli d show GENERAL.DEVICE: ens18 GENERAL.TYPE: ethernet GENERAL.HWADDR: 92:86:D7:66:E7:5A GENERAL.MTU: 1500 GENERAL.STATE: 100 (connected) GENERAL.CONNECTION: ens18 GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/2 WIRED-PROPERTIES.CARRIER: on IP4.ADDRESS[1]: 10.0.2.101/24 IP4.GATEWAY: 10.0.2.1 IP4.ROUTE[1]: dst = 10.0.2.0/24, nh = 0.0.0.0, mt = 100 IP4.ROUTE[2]: dst = 0.0.0.0/0, nh = 10.0.2.1, mt = 100 IP4.DNS[1]: 8.8.8.8 IP6.ADDRESS[1]: fe80::9086:d7ff:fe66:e75a/64 IP6.GATEWAY: -- IP6.ROUTE[1]: dst = fe80::/64, nh = ::, mt = 1024 GENERAL.DEVICE: lo GENERAL.TYPE: loopback GENERAL.HWADDR: 00:00:00:00:00:00 GENERAL.MTU: 65536 GENERAL.STATE: 100 (connected (externally)) GENERAL.CONNECTION: lo GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/1 IP4.ADDRESS[1]: 127.0.0.1/8 IP4.GATEWAY: -- IP6.ADDRESS[1]: ::1/128 IP6.GATEWAY: -- IP6.ROUTE[1]: dst = ::1/128, nh = ::, mt = 256
Pour activer le profil ip_fixe, utilisez la commande suivante :
[root@centos8 ~]# nmcli connection up ip_fixe
Notez que votre terminal est bloqué à cause du changement de l'adresse IP.
A faire - Revenez à l'accueil de Guacamole et re-connectez-vous à la VM en tant que trainee en utilisant la connexion RedHat9_SSH_10.0.2.102.
Le profil ip_fixe est maintenant activé tandis que le profil ens18 a été désactivé :
[root@redhat9 ~]# nmcli c show NAME UUID TYPE DEVICE ip_fixe b3d51921-4deb-4975-ad52-f31993b2af0c ethernet ens18 lo 8df82174-1d45-4506-9248-6bfcd2d20240 loopback lo ens18 ea4c8254-6236-3130-8323-8b3f71d807a1 ethernet -- [root@redhat9 ~]# nmcli d show GENERAL.DEVICE: ens18 GENERAL.TYPE: ethernet GENERAL.HWADDR: 92:86:D7:66:E7:5A GENERAL.MTU: 1500 GENERAL.STATE: 100 (connected) GENERAL.CONNECTION: ip_fixe GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/3 WIRED-PROPERTIES.CARRIER: on IP4.ADDRESS[1]: 10.0.2.102/24 IP4.GATEWAY: 10.0.2.1 IP4.ROUTE[1]: dst = 10.0.2.0/24, nh = 0.0.0.0, mt = 100 IP4.ROUTE[2]: dst = 0.0.0.0/0, nh = 10.0.2.1, mt = 100 IP6.ADDRESS[1]: fe80::2da3:cf78:c904:b9b9/64 IP6.GATEWAY: -- IP6.ROUTE[1]: dst = fe80::/64, nh = ::, mt = 1024 GENERAL.DEVICE: lo GENERAL.TYPE: loopback GENERAL.HWADDR: 00:00:00:00:00:00 GENERAL.MTU: 65536 GENERAL.STATE: 100 (connected (externally)) GENERAL.CONNECTION: lo GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/1 IP4.ADDRESS[1]: 127.0.0.1/8 IP4.GATEWAY: -- IP6.ADDRESS[1]: ::1/128 IP6.GATEWAY: -- IP6.ROUTE[1]: dst = ::1/128, nh = ::, mt = 256
Pour consulter les paramètres du profil ens18, utilisez la commande suivante :
[root@redhat9 ~]# nmcli -p connection show ens18
===============================================================================
Connection profile details (ens18)
===============================================================================
connection.id: ens18
connection.uuid: ea4c8254-6236-3130-8323-8b3f71d807a1
connection.stable-id: --
connection.type: 802-3-ethernet
connection.interface-name: ens18
connection.autoconnect: yes
connection.autoconnect-priority: -999
connection.autoconnect-retries: -1 (default)
connection.multi-connect: 0 (default)
connection.auth-retries: -1
connection.timestamp: 1727605468
connection.permissions: --
connection.zone: --
connection.controller: --
connection.master: --
connection.slave-type: --
connection.port-type: --
connection.autoconnect-slaves: -1 (default)
connection.autoconnect-ports: -1 (default)
connection.secondaries: --
connection.gateway-ping-timeout: 0
connection.metered: unknown
connection.lldp: default
connection.mdns: -1 (default)
connection.llmnr: -1 (default)
connection.dns-over-tls: -1 (default)
connection.mptcp-flags: 0x0 (default)
connection.wait-device-timeout: -1
connection.wait-activation-delay: -1
-------------------------------------------------------------------------------
802-3-ethernet.port: --
802-3-ethernet.speed: 0
802-3-ethernet.duplex: --
802-3-ethernet.auto-negotiate: no
802-3-ethernet.mac-address: --
802-3-ethernet.cloned-mac-address: --
802-3-ethernet.generate-mac-address-mask:--
802-3-ethernet.mac-address-blacklist: --
802-3-ethernet.mtu: auto
802-3-ethernet.s390-subchannels: --
802-3-ethernet.s390-nettype: --
802-3-ethernet.s390-options: --
802-3-ethernet.wake-on-lan: default
802-3-ethernet.wake-on-lan-password: --
802-3-ethernet.accept-all-mac-addresses:-1 (default)
-------------------------------------------------------------------------------
ipv4.method: manual
ipv4.dns: 8.8.8.8
ipv4.dns-search: --
ipv4.dns-options: --
ipv4.dns-priority: 0
ipv4.addresses: 10.0.2.101/24
lines 1-55
[q]
De même, pour consulter les paramètres du profil ip_fixe, utilisez la commande suivante :
[root@redhat9 ~]# nmcli -p connection show ip_fixe
===============================================================================
Connection profile details (ip_fixe)
===============================================================================
connection.id: ip_fixe
connection.uuid: b3d51921-4deb-4975-ad52-f31993b2af0c
connection.stable-id: --
connection.type: 802-3-ethernet
connection.interface-name: ens18
connection.autoconnect: yes
connection.autoconnect-priority: 0
connection.autoconnect-retries: -1 (default)
connection.multi-connect: 0 (default)
connection.auth-retries: -1
connection.timestamp: 1727605469
connection.permissions: --
connection.zone: --
connection.controller: --
connection.master: --
connection.slave-type: --
connection.port-type: --
connection.autoconnect-slaves: -1 (default)
connection.autoconnect-ports: -1 (default)
connection.secondaries: --
connection.gateway-ping-timeout: 0
connection.metered: unknown
connection.lldp: default
connection.mdns: -1 (default)
connection.llmnr: -1 (default)
connection.dns-over-tls: -1 (default)
connection.mptcp-flags: 0x0 (default)
connection.wait-device-timeout: -1
connection.wait-activation-delay: -1
-------------------------------------------------------------------------------
802-3-ethernet.port: --
802-3-ethernet.speed: 0
802-3-ethernet.duplex: --
802-3-ethernet.auto-negotiate: no
802-3-ethernet.mac-address: --
802-3-ethernet.cloned-mac-address: --
802-3-ethernet.generate-mac-address-mask:--
802-3-ethernet.mac-address-blacklist: --
802-3-ethernet.mtu: auto
802-3-ethernet.s390-subchannels: --
802-3-ethernet.s390-nettype: --
802-3-ethernet.s390-options: --
802-3-ethernet.wake-on-lan: default
802-3-ethernet.wake-on-lan-password: --
802-3-ethernet.accept-all-mac-addresses:-1 (default)
-------------------------------------------------------------------------------
ipv4.method: manual
ipv4.dns: --
ipv4.dns-search: --
ipv4.dns-options: --
ipv4.dns-priority: 0
ipv4.addresses: 10.0.2.102/24
lines 1-55
[q]
Pour consulter la liste profils associés à un périphérique, utilisez la commande suivante :
[root@redhat9 ~]# nmcli -f CONNECTIONS device show ens18 CONNECTIONS.AVAILABLE-CONNECTION-PATHS: /org/freedesktop/NetworkManager/Settings/1,/org/freedesktop/NetworkManager/Settings/3 CONNECTIONS.AVAILABLE-CONNECTIONS[1]: ea4c8254-6236-3130-8323-8b3f71d807a1 | ens18 CONNECTIONS.AVAILABLE-CONNECTIONS[2]: b3d51921-4deb-4975-ad52-f31993b2af0c | ip_fixe
Les fichiers de configuration pour le periphérique ens18 se trouvent dans le répertoire /etc/NetworkManager/system-connections :
[root@redhat9 ~]# ls -l /etc/NetworkManager/system-connections total 8 -rw-------. 1 root root 253 Oct 19 2023 ens18.nmconnection -rw-------. 1 root root 218 Sep 29 12:21 ip_fixe.nmconnection
1.2 - Résolution des Noms
L'étude du fichier /etc/NetworkManager/system-connections/ip_fixe.nmconnection démontre l'abscence de directives concernant les DNS :
[root@redhat9 ~]# cat /etc/NetworkManager/system-connections/ip_fixe.nmconnection [connection] id=ip_fixe uuid=b3d51921-4deb-4975-ad52-f31993b2af0c type=ethernet interface-name=ens18 [ethernet] [ipv4] address1=10.0.2.102/24,10.0.2.1 method=manual [ipv6] addr-gen-mode=default method=auto [proxy]
La résolution des noms est donc inactive :
[root@redhat9 ~]# ping www.free.fr ping: www.free.fr: Name or service not known
Modifiez donc la configuration du profil ip_fixe :
[root@redhat9 ~]# nmcli connection mod ip_fixe ipv4.dns 8.8.8.8
L'étude du fichier /etc/NetworkManager/system-connections/ip_fixe.nmconnection démontre que la directive concernant le serveur DNS a été ajoutée :
[root@redhat9 ~]# cat /etc/NetworkManager/system-connections/ip_fixe.nmconnection [connection] id=ip_fixe uuid=b3d51921-4deb-4975-ad52-f31993b2af0c type=ethernet interface-name=ens18 timestamp=1727605469 [ethernet] [ipv4] address1=10.0.2.102/24,10.0.2.1 dns=8.8.8.8; method=manual [ipv6] addr-gen-mode=default method=auto [proxy]
Afin que la modification du serveur DNS soit prise en compte, re-démarrez le service NetworkManager :
[root@redhat9 ~]# systemctl restart NetworkManager.service
[root@redhat9 ~]# systemctl status NetworkManager.service
● NetworkManager.service - Network Manager
Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled; preset: enabled)
Active: active (running) since Sun 2024-09-29 12:36:35 CEST; 11s ago
Docs: man:NetworkManager(8)
Main PID: 4456 (NetworkManager)
Tasks: 4 (limit: 48800)
Memory: 5.5M
CPU: 82ms
CGroup: /system.slice/NetworkManager.service
└─4456 /usr/sbin/NetworkManager --no-daemon
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5342] device (lo): state change: secondaries -> activated (reason 'none', sys-iface-state: 'external')
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5347] device (lo): Activation: successful, device activated.
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5360] device (ens18): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'assume')
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5654] device (ens18): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'assume')
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5660] device (ens18): state change: secondaries -> activated (reason 'none', sys-iface-state: 'assume')
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5663] manager: NetworkManager state is now CONNECTED_SITE
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5666] device (ens18): Activation: successful, device activated.
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5671] manager: NetworkManager state is now CONNECTED_GLOBAL
Sep 29 12:36:35 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606195.5673] manager: startup complete
Sep 29 12:36:36 redhat9.ittraining.loc NetworkManager[4456]: <info> [1727606196.0852] agent-manager: agent[923443df876692f7,:1.25/org.gnome.Shell.NetworkAgent/42]: agent registered
Vérifiez que le fichier /etc/resolv.conf ait été modifié par NetworkManager :
[root@redhat9 ~]# cat /etc/resolv.conf # Generated by NetworkManager search ittraining.loc nameserver 8.8.8.8
Dernièrement vérifiez la resolution des noms :
[root@redhat9 ~]# ping www.free.fr PING www.free.fr (212.27.48.10) 56(84) bytes of data. 64 bytes from www.free.fr (212.27.48.10): icmp_seq=1 ttl=47 time=89.2 ms 64 bytes from www.free.fr (212.27.48.10): icmp_seq=2 ttl=47 time=89.2 ms 64 bytes from www.free.fr (212.27.48.10): icmp_seq=3 ttl=47 time=89.3 ms ^C --- www.free.fr ping statistics --- 4 packets transmitted, 3 received, 25% packet loss, time 3005ms rtt min/avg/max/mdev = 89.153/89.186/89.252/0.046 ms
Important : Notez qu'il existe un front-end graphique en mode texte, nmtui, pour configurer NetworkManager.
1.3 - Ajouter une Deuxième Adresse IP à un Profil
Pour ajouter une deuxième adresse IP à un profil sous RHEL/CentOS 8, il convient d'utiliser la commande suivante :
[root@redhat9 ~]# nmcli connection mod ip_fixe +ipv4.addresses 192.168.1.2/24
Rechargez la configuration du profil :
[root@redhat9 ~]# nmcli con up ip_fixe Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/3)
Saisissez ensuite la commande suivante :
[root@redhat9 ~]# nmcli connection show ip_fixe connection.id: ip_fixe connection.uuid: b3d51921-4deb-4975-ad52-f31993b2af0c connection.stable-id: -- connection.type: 802-3-ethernet connection.interface-name: ens18 connection.autoconnect: yes connection.autoconnect-priority: 0 connection.autoconnect-retries: -1 (default) connection.multi-connect: 0 (default) connection.auth-retries: -1 connection.timestamp: 1727606325 connection.permissions: -- connection.zone: -- connection.controller: -- connection.master: -- connection.slave-type: -- connection.port-type: -- connection.autoconnect-slaves: -1 (default) connection.autoconnect-ports: -1 (default) connection.secondaries: -- connection.gateway-ping-timeout: 0 connection.metered: unknown connection.lldp: default connection.mdns: -1 (default) connection.llmnr: -1 (default) connection.dns-over-tls: -1 (default) connection.mptcp-flags: 0x0 (default) connection.wait-device-timeout: -1 connection.wait-activation-delay: -1 802-3-ethernet.port: -- 802-3-ethernet.speed: 0 802-3-ethernet.duplex: -- 802-3-ethernet.auto-negotiate: no 802-3-ethernet.mac-address: -- 802-3-ethernet.cloned-mac-address: -- 802-3-ethernet.generate-mac-address-mask:-- 802-3-ethernet.mac-address-blacklist: -- 802-3-ethernet.mtu: auto 802-3-ethernet.s390-subchannels: -- 802-3-ethernet.s390-nettype: -- 802-3-ethernet.s390-options: -- 802-3-ethernet.wake-on-lan: default 802-3-ethernet.wake-on-lan-password: -- 802-3-ethernet.accept-all-mac-addresses:-1 (default) ipv4.method: manual ipv4.dns: 8.8.8.8 ipv4.dns-search: -- ipv4.dns-options: -- ipv4.dns-priority: 0 ipv4.addresses: 10.0.2.102/24, 192.168.1.2/24 ipv4.gateway: 10.0.2.1 ipv4.routes: -- ipv4.route-metric: -1 ipv4.route-table: 0 (unspec) ipv4.routing-rules: -- ipv4.replace-local-rule: -1 (default) ipv4.ignore-auto-routes: no ipv4.ignore-auto-dns: no ipv4.dhcp-client-id: -- ipv4.dhcp-iaid: -- ipv4.dhcp-dscp: -- ipv4.dhcp-timeout: 0 (default) ipv4.dhcp-send-hostname: yes ipv4.dhcp-hostname: -- ipv4.dhcp-fqdn: -- ipv4.dhcp-hostname-flags: 0x0 (none) ipv4.never-default: no ipv4.may-fail: yes ipv4.required-timeout: -1 (default) ipv4.dad-timeout: -1 (default) ipv4.dhcp-vendor-class-identifier: -- ipv4.link-local: 0 (default) ipv4.dhcp-reject-servers: -- ipv4.auto-route-ext-gw: -1 (default) ipv6.method: auto ipv6.dns: -- ipv6.dns-search: -- ipv6.dns-options: -- ipv6.dns-priority: 0 ipv6.addresses: -- ipv6.gateway: -- ipv6.routes: -- ipv6.route-metric: -1 ipv6.route-table: 0 (unspec) ipv6.routing-rules: -- ipv6.replace-local-rule: -1 (default) ipv6.ignore-auto-routes: no ipv6.ignore-auto-dns: no ipv6.never-default: no ipv6.may-fail: yes ipv6.required-timeout: -1 (default) ipv6.ip6-privacy: -1 (unknown) ipv6.addr-gen-mode: default ipv6.ra-timeout: 0 (default) ipv6.mtu: auto ipv6.dhcp-pd-hint: -- ipv6.dhcp-duid: -- ipv6.dhcp-iaid: -- ipv6.dhcp-timeout: 0 (default) ipv6.dhcp-send-hostname: yes ipv6.dhcp-hostname: -- ipv6.dhcp-hostname-flags: 0x0 (none) ipv6.auto-route-ext-gw: -1 (default) ipv6.token: -- proxy.method: none proxy.browser-only: no proxy.pac-url: -- proxy.pac-script: -- GENERAL.NAME: ip_fixe GENERAL.UUID: b3d51921-4deb-4975-ad52-f31993b2af0c GENERAL.DEVICES: ens18 GENERAL.IP-IFACE: ens18 GENERAL.STATE: activated GENERAL.DEFAULT: yes GENERAL.DEFAULT6: no GENERAL.SPEC-OBJECT: -- GENERAL.VPN: no GENERAL.DBUS-PATH: /org/freedesktop/NetworkManager/ActiveConnection/3 GENERAL.CON-PATH: /org/freedesktop/NetworkManager/Settings/3 GENERAL.ZONE: -- GENERAL.MASTER-PATH: -- IP4.ADDRESS[1]: 192.168.1.2/24 IP4.ADDRESS[2]: 10.0.2.102/24 IP4.GATEWAY: 10.0.2.1 IP4.ROUTE[1]: dst = 10.0.2.0/24, nh = 0.0.0.0, mt = 100 IP4.ROUTE[2]: dst = 192.168.1.0/24, nh = 0.0.0.0, mt = 100 IP4.ROUTE[3]: dst = 0.0.0.0/0, nh = 10.0.2.1, mt = 100 IP4.DNS[1]: 8.8.8.8 IP6.ADDRESS[1]: fe80::2da3:cf78:c904:b9b9/64 IP6.GATEWAY: -- IP6.ROUTE[1]: dst = fe80::/64, nh = ::, mt = 1024 lines 77-131/131 (END) [q]
Important : Notez l'ajout de l'adresse secondaire à la ligne ipv4.addresses: ainsi que l'ajout de la ligne IP4.ADDRESS[2]:.
Consultez maintenant le contenu du fichier /etc/NetworkManager/system-connections/ip_fixe.nmconnection :
[root@redhat9 ~]# cat /etc/NetworkManager/system-connections/ip_fixe.nmconnection [connection] id=ip_fixe uuid=b3d51921-4deb-4975-ad52-f31993b2af0c type=ethernet interface-name=ens18 timestamp=1727606195 [ethernet] [ipv4] address1=10.0.2.102/24,10.0.2.1 address2=192.168.1.2/24 dns=8.8.8.8; method=manual [ipv6] addr-gen-mode=default method=auto [proxy]
Important : Notez l'ajout de la ligne address2=192.168.1.2/24.
1.4 - La Commande hostname
La procédure de la modification du hostname est simplifiée et sa prise en compte est immédiate :
[root@redhat9 ~]# hostname redhat9.ittraining.loc [root@redhat9 ~]# cat /etc/hostname redhat9.ittraining.loc [root@redhat9 ~]# nmcli general hostname redhat.ittraining.loc [root@redhat9 ~]# cat /etc/hostname redhat.ittraining.loc [root@redhat9 ~]# nmcli general hostname redhat9.ittraining.loc [root@redhat9 ~]# cat /etc/hostname redhat9.ittraining.loc [root@redhat9 ~]# hostname redhat9.ittraining.loc
1.5 - La Commande ip
Sous RHEL 9 la commande ip est préférée par rapport à la commande ifconfig :
[root@redhat9 ~]# ip address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 92:86:d7:66:e7:5a brd ff:ff:ff:ff:ff:ff
altname enp0s18
inet 10.0.2.102/24 brd 10.0.2.255 scope global noprefixroute ens18
valid_lft forever preferred_lft forever
inet 192.168.1.2/24 brd 192.168.1.255 scope global noprefixroute ens18
valid_lft forever preferred_lft forever
inet6 fe80::2da3:cf78:c904:b9b9/64 scope link noprefixroute
valid_lft forever preferred_lft forever
Options de la Commande ip
Les options de cette commande sont :
[root@redhat9 ~]# ip --help
Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }
ip [ -force ] -batch filename
where OBJECT := { address | addrlabel | amt | fou | help | ila | ioam | l2tp |
link | macsec | maddress | monitor | mptcp | mroute | mrule |
neighbor | neighbour | netconf | netns | nexthop | ntable |
ntbl | route | rule | sr | tap | tcpmetrics |
token | tunnel | tuntap | vrf | xfrm }
OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |
-h[uman-readable] | -iec | -j[son] | -p[retty] |
-f[amily] { inet | inet6 | mpls | bridge | link } |
-4 | -6 | -M | -B | -0 |
-l[oops] { maximum-addr-flush-attempts } | -br[ief] |
-o[neline] | -t[imestamp] | -ts[hort] | -b[atch] [filename] |
-rc[vbuf] [size] | -n[etns] name | -N[umeric] | -a[ll] |
-c[olor]}
1.6 - Activer/Désactiver une Interface Manuellement
Deux commandes existent pour désactiver et activer manuellement une interface réseau :
# nmcli device disconnect enp0s3 # nmcli device connect enp0s3
Important : Veuillez ne PAS exécuter ces deux commandes.
1.7 - Routage Statique
La commande ip
Sous RHEL 9, pour supprimer la route vers le réseau 192.168.1.0 il convient d'utiliser la commande ip et non pas la commande route :
[root@redhat9 ~]# ip route default via 10.0.2.1 dev ens18 proto static metric 100 10.0.2.0/24 dev ens18 proto kernel scope link src 10.0.2.102 metric 100 192.168.1.0/24 dev ens18 proto kernel scope link src 192.168.1.2 metric 100 [root@redhat9 ~]# ip route del 192.168.1.0/24 via 0.0.0.0 [root@redhat9 ~]# ip route default via 10.0.2.1 dev ens18 proto static metric 100 10.0.2.0/24 dev ens18 proto kernel scope link src 10.0.2.102 metric 100
Pour ajouter la route vers le réseau 192.168.1.0 :
[root@redhat9 ~]# ip route add 192.168.1.0/24 via 10.0.2.1 [root@redhat9 ~]# ip route default via 10.0.2.1 dev ens18 proto static metric 100 10.0.2.0/24 dev ens18 proto kernel scope link src 10.0.2.102 metric 100 192.168.1.0/24 via 10.0.2.1 dev ens18
Important - La commande utilisée pour ajouter une passerelle par défaut prend la forme suivante ip route add default via adresse ip.
Activer le routage sur le serveur
Pour activer le routage IPv4 sur le serveur, il convient d'activer la retransmission des paquets:
[root@redhat9 ~]# cat /proc/sys/net/ipv4/ip_forward 0 [root@redhat9 ~]# echo 1 > /proc/sys/net/ipv4/ip_forward [root@redhat9 ~]# cat /proc/sys/net/ipv4/ip_forward 1
Pour activer le routage IPv6 sur le serveur, il convient d'activer la retransmission des paquets:
[root@redhat9 ~]# cat /proc/sys/net/ipv6/conf/all/forwarding 0 [root@redhat9 ~]# echo "1" > /proc/sys/net/ipv6/conf/all/forwarding [root@redhat9 ~]# cat /proc/sys/net/ipv6/conf/all/forwarding 1
LAB #2 - Diagnostique du Réseau
2.1 - ping
Pour tester l'accessibilité d'une machine, vous devez utiliser la commande ping :
[root@redhat9 ~]# ping -c4 10.0.2.1 PING 10.0.2.1 (10.0.2.1) 56(84) bytes of data. 64 bytes from 10.0.2.1: icmp_seq=1 ttl=64 time=0.157 ms 64 bytes from 10.0.2.1: icmp_seq=2 ttl=64 time=0.130 ms 64 bytes from 10.0.2.1: icmp_seq=3 ttl=64 time=0.212 ms 64 bytes from 10.0.2.1: icmp_seq=4 ttl=64 time=0.222 ms --- 10.0.2.1 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3104ms rtt min/avg/max/mdev = 0.130/0.180/0.222/0.038 ms
Options de la commande ping
Les options de cette commande sont :
[root@redhat9 ~]# ping --help ping: invalid option -- '-' Usage ping [options] <destination> Options: <destination> dns name or ip address -a use audible ping -A use adaptive ping -B sticky source address -c <count> stop after <count> replies -D print timestamps -d use SO_DEBUG socket option -f flood ping -h print help and exit -I <interface> either interface name or address -i <interval> seconds between sending each packet -L suppress loopback of multicast packets -l <preload> send <preload> number of packages while waiting replies -m <mark> tag the packets going out -M <pmtud opt> define mtu discovery, can be one of <do|dont|want> -n no dns name resolution -O report outstanding replies -p <pattern> contents of padding byte -q quiet output -Q <tclass> use quality of service <tclass> bits -s <size> use <size> as number of data bytes to be sent -S <size> use <size> as SO_SNDBUF socket option value -t <ttl> define time to live -U print user-to-user latency -v verbose output -V print version and exit -w <deadline> reply wait <deadline> in seconds -W <timeout> time to wait for response IPv4 options: -4 use IPv4 -b allow pinging broadcast -R record route -T <timestamp> define timestamp, can be one of <tsonly|tsandaddr|tsprespec> IPv6 options: -6 use IPv6 -F <flowlabel> define flow label, default is random -N <nodeinfo opt> use icmp6 node info query, try <help> as argument For more details see ping(8).
2.2 - netstat -i
Pour visualiser les statistiques réseaux, vous disposez de la commande netstat :
[root@redhat9 ~]# netstat -i Kernel Interface table Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg ens18 1500 18785 0 0 0 12157 0 0 0 BMRU lo 65536 105 0 0 0 105 0 0 0 LRU
Options de la commande netstat
Les options de cette commande sont :
[root@redhat9 ~]# netstat --help
usage: netstat [-vWeenNcCF] [<Af>] -r netstat {-V|--version|-h|--help}
netstat [-vWnNcaeol] [<Socket> ...]
netstat { [-vWeenNac] -I[<Iface>] | [-veenNac] -i | [-cnNe] -M | -s [-6tuw] } [delay]
-r, --route display routing table
-I, --interfaces=<Iface> display interface table for <Iface>
-i, --interfaces display interface table
-g, --groups display multicast group memberships
-s, --statistics display networking statistics (like SNMP)
-M, --masquerade display masqueraded connections
-v, --verbose be verbose
-W, --wide don't truncate IP addresses
-n, --numeric don't resolve names
--numeric-hosts don't resolve host names
--numeric-ports don't resolve port names
--numeric-users don't resolve user names
-N, --symbolic resolve hardware names
-e, --extend display other/more information
-p, --programs display PID/Program name for sockets
-o, --timers display timers
-c, --continuous continuous listing
-l, --listening display listening server sockets
-a, --all display all sockets (default: connected)
-F, --fib display Forwarding Information Base (default)
-C, --cache display routing cache instead of FIB
-Z, --context display SELinux security context for sockets
<Socket>={-t|--tcp} {-u|--udp} {-U|--udplite} {-S|--sctp} {-w|--raw}
{-x|--unix} --ax25 --ipx --netrom
<AF>=Use '-6|-4' or '-A <af>' or '--<af>'; default: inet
List of possible address families (which support routing):
inet (DARPA Internet) inet6 (IPv6) ax25 (AMPR AX.25)
netrom (AMPR NET/ROM) ipx (Novell IPX) ddp (Appletalk DDP)
x25 (CCITT X.25)
2.3 - traceroute
La commande ping est à la base de la commande traceroute. Cette commande sert à découvrir la route empruntée pour accéder à un site donné :
[root@redhat9 ~]# traceroute www.ittraining.team bash: traceroute: command not found... Install package 'traceroute' to provide command 'traceroute'? [N/y] y * Waiting in queue... * Loading list of packages.... The following packages have to be installed: traceroute-3:2.1.0-18.el9.x86_64 Traces the route taken by packets over an IPv4/IPv6 network Proceed with changes? [N/y] y * Waiting in queue... * Waiting for authentication... * Waiting in queue... * Downloading packages... * Requesting data... * Testing changes... * Installing packages... traceroute to www.ittraining.team (136.143.190.199), 30 hops max, 60 byte packets 1 _gateway (10.0.2.1) 0.437 ms 0.396 ms 0.380 ms 2 51.79.19.252 (51.79.19.252) 0.554 ms 0.689 ms 0.818 ms 3 10.161.82.50 (10.161.82.50) 0.372 ms 10.161.82.52 (10.161.82.52) 0.444 ms 10.161.82.50 (10.161.82.50) 0.372 ms 4 10.34.98.50 (10.34.98.50) 0.483 ms 0.580 ms 0.973 ms 5 10.74.8.92 (10.74.8.92) 0.232 ms 10.74.8.90 (10.74.8.90) 9.825 ms 10.74.8.94 (10.74.8.94) 0.206 ms 6 10.95.81.10 (10.95.81.10) 0.712 ms 10.95.81.8 (10.95.81.8) 1.103 ms 10.95.81.10 (10.95.81.10) 1.435 ms 7 be101.chi-ch2-sbb1-8k.il.us (198.27.73.207) 17.425 ms be101.chi-ch2-sbb2-8k.il.us (192.99.146.141) 17.089 ms be101.chi-ch2-sbb1-8k.il.us (198.27.73.207) 17.055 ms 8 * * * 9 10.200.1.1 (10.200.1.1) 66.593 ms 68.592 ms * 10 * 10.200.1.1 (10.200.1.1) 68.518 ms * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * *^C
Options de la commande traceroute
Les options de cette commande sont :
[root@redhat9 ~]# traceroute --help
Usage:
traceroute [ -46dFITnreAUDV ] [ -f first_ttl ] [ -g gate,... ] [ -i device ] [ -m max_ttl ] [ -N squeries ] [ -p port ] [ -t tos ] [ -l flow_label ] [ -w MAX,HERE,NEAR ] [ -q nqueries ] [ -s src_addr ] [ -z sendwait ] [ --fwmark=num ] host [ packetlen ]
Options:
-4 Use IPv4
-6 Use IPv6
-d --debug Enable socket level debugging
-F --dont-fragment Do not fragment packets
-f first_ttl --first=first_ttl
Start from the first_ttl hop (instead from 1)
-g gate,... --gateway=gate,...
Route packets through the specified gateway
(maximum 8 for IPv4 and 127 for IPv6)
-I --icmp Use ICMP ECHO for tracerouting
-T --tcp Use TCP SYN for tracerouting (default port is 80)
-i device --interface=device
Specify a network interface to operate with
-m max_ttl --max-hops=max_ttl
Set the max number of hops (max TTL to be
reached). Default is 30
-N squeries --sim-queries=squeries
Set the number of probes to be tried
simultaneously (default is 16)
-n Do not resolve IP addresses to their domain names
-p port --port=port Set the destination port to use. It is either
initial udp port value for "default" method
(incremented by each probe, default is 33434), or
initial seq for "icmp" (incremented as well,
default from 1), or some constant destination
port for other methods (with default of 80 for
"tcp", 53 for "udp", etc.)
-t tos --tos=tos Set the TOS (IPv4 type of service) or TC (IPv6
traffic class) value for outgoing packets
-l flow_label --flowlabel=flow_label
Use specified flow_label for IPv6 packets
-w MAX,HERE,NEAR --wait=MAX,HERE,NEAR
Wait for a probe no more than HERE (default 3)
times longer than a response from the same hop,
or no more than NEAR (default 10) times than some
next hop, or MAX (default 5.0) seconds (float
point values allowed too)
-q nqueries --queries=nqueries
Set the number of probes per each hop. Default is
3
-r Bypass the normal routing and send directly to a
host on an attached network
-s src_addr --source=src_addr
Use source src_addr for outgoing packets
-z sendwait --sendwait=sendwait
Minimal time interval between probes (default 0).
If the value is more than 10, then it specifies a
number in milliseconds, else it is a number of
seconds (float point values allowed too)
-e --extensions Show ICMP extensions (if present), including MPLS
-A --as-path-lookups Perform AS path lookups in routing registries and
print results directly after the corresponding
addresses
-M name --module=name Use specified module (either builtin or external)
for traceroute operations. Most methods have
their shortcuts (`-I' means `-M icmp' etc.)
-O OPTS,... --options=OPTS,...
Use module-specific option OPTS for the
traceroute module. Several OPTS allowed,
separated by comma. If OPTS is "help", print info
about available options
--sport=num Use source port num for outgoing packets. Implies
`-N 1'
--fwmark=num Set firewall mark for outgoing packets
-U --udp Use UDP to particular port for tracerouting
(instead of increasing the port per each probe),
default port is 53
-UL Use UDPLITE for tracerouting (default dest port
is 53)
-D --dccp Use DCCP Request for tracerouting (default port
is 33434)
-P prot --protocol=prot Use raw packet of protocol prot for tracerouting
--mtu Discover MTU along the path being traced. Implies
`-F -N 1'
--back Guess the number of hops in the backward path and
print if it differs
-V --version Print version info and exit
--help Read this help and exit
Arguments:
+ host The host to traceroute to
packetlen The full packet length (default is the length of an IP
header plus 40). Can be ignored or increased to a minimal
allowed value
LAB #3 - Connexions à Distance
3.1 - Telnet
Important - Si la commande telnet n'est pas installée sous RedHat 9, installez-le à l'aide de la commande dnf install telnet en tant que root.
La commande telnet est utilisée pour établir une connexion à distance avec un serveur telnet :
# telnet numero_ip
Important - Le service telnet revient à une redirection des canaux standards d'entrée et de sortie. Notez que la connexion n'est pas sécurisée. Pour fermer la connexion, il faut saisir la commande exit. La commande telnet n'offre pas de services de transfert de fichiers. Pour cela, il convient d'utiliser la command ftp.
Options de la commande telnet
Les options de cette commande sont :
[root@redhat9 ~]# telnet --help
telnet: invalid option -- '-'
Usage: telnet [-4] [-6] [-8] [-E] [-L] [-S tos] [-a] [-c] [-d] [-e char] [-l user]
[-n tracefile] [-b hostalias ] [-r]
[host-name [port]]
3.2 - wget
La commande wget est utilisée pour récupérer un fichier via http, https ou ftp :
[root@redhat9 ~]# wget https://www.dropbox.com/scl/fi/c0cbo91y2i7qwjexeldgt/wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx --2024-09-29 13:56:10-- https://www.dropbox.com/scl/fi/c0cbo91y2i7qwjexeldgt/wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx Resolving www.dropbox.com (www.dropbox.com)... 162.125.11.18, 2620:100:6050:18::a27d:b12 Connecting to www.dropbox.com (www.dropbox.com)|162.125.11.18|:443... connected. HTTP request sent, awaiting response... 302 Found Location: https://uc22f408c6cacfcc03fb4dbb269d.dl.dropboxusercontent.com/cd/0/inline/CbfNI4-pa7NlBqzKN3_KWHUoXFn8kcMiV99ekpnDl2iVRanx9yx3YdpDcC5FHk8MJqHFfDnbPFeENko4TWJUAKMwZJ82s18b69iKmgbpMCFyd5oGQHLZs6uB3xy0_nmJl59Ru2MjCGeyEo9ikQ3UaaqY/file# [following] --2024-09-29 13:56:11-- https://uc22f408c6cacfcc03fb4dbb269d.dl.dropboxusercontent.com/cd/0/inline/CbfNI4-pa7NlBqzKN3_KWHUoXFn8kcMiV99ekpnDl2iVRanx9yx3YdpDcC5FHk8MJqHFfDnbPFeENko4TWJUAKMwZJ82s18b69iKmgbpMCFyd5oGQHLZs6uB3xy0_nmJl59Ru2MjCGeyEo9ikQ3UaaqY/file Resolving uc22f408c6cacfcc03fb4dbb269d.dl.dropboxusercontent.com (uc22f408c6cacfcc03fb4dbb269d.dl.dropboxusercontent.com)... 162.125.11.15, 2620:100:6050:15::a27d:b0f Connecting to uc22f408c6cacfcc03fb4dbb269d.dl.dropboxusercontent.com (uc22f408c6cacfcc03fb4dbb269d.dl.dropboxusercontent.com)|162.125.11.15|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 46 [text/plain] Saving to: ‘wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx’ wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx 100%[====================================================================================================================>] 46 --.-KB/s in 0s 2024-09-29 13:56:11 (40.9 MB/s) - ‘wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx’ saved [46/46] [root@redhat9 ~]# cat wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx This is a file retrieved by the wget command.
Options de la commande wget
Les options de cette commande sont :
[root@redhat9 ~]# wget --help
GNU Wget 1.21.1, a non-interactive network retriever.
Usage: wget [OPTION]... [URL]...
Mandatory arguments to long options are mandatory for short options too.
Startup:
-V, --version display the version of Wget and exit
-h, --help print this help
-b, --background go to background after startup
-e, --execute=COMMAND execute a `.wgetrc'-style command
Logging and input file:
-o, --output-file=FILE log messages to FILE
-a, --append-output=FILE append messages to FILE
-d, --debug print lots of debugging information
-q, --quiet quiet (no output)
-v, --verbose be verbose (this is the default)
-nv, --no-verbose turn off verboseness, without being quiet
--report-speed=TYPE output bandwidth as TYPE. TYPE can be bits
-i, --input-file=FILE download URLs found in local or external FILE
-F, --force-html treat input file as HTML
-B, --base=URL resolves HTML input-file links (-i -F)
relative to URL
--config=FILE specify config file to use
--no-config do not read any config file
--rejected-log=FILE log reasons for URL rejection to FILE
Download:
-t, --tries=NUMBER set number of retries to NUMBER (0 unlimits)
--retry-connrefused retry even if connection is refused
--retry-on-http-error=ERRORS comma-separated list of HTTP errors to retry
-O, --output-document=FILE write documents to FILE
-nc, --no-clobber skip downloads that would download to
existing files (overwriting them)
--no-netrc don't try to obtain credentials from .netrc
-c, --continue resume getting a partially-downloaded file
--start-pos=OFFSET start downloading from zero-based position OFFSET
--progress=TYPE select progress gauge type
--show-progress display the progress bar in any verbosity mode
-N, --timestamping don't re-retrieve files unless newer than
local
--no-if-modified-since don't use conditional if-modified-since get
requests in timestamping mode
--no-use-server-timestamps don't set the local file's timestamp by
the one on the server
-S, --server-response print server response
--spider don't download anything
-T, --timeout=SECONDS set all timeout values to SECONDS
--dns-timeout=SECS set the DNS lookup timeout to SECS
--connect-timeout=SECS set the connect timeout to SECS
--read-timeout=SECS set the read timeout to SECS
-w, --wait=SECONDS wait SECONDS between retrievals
(applies if more then 1 URL is to be retrieved)
--waitretry=SECONDS wait 1..SECONDS between retries of a retrieval
(applies if more then 1 URL is to be retrieved)
--random-wait wait from 0.5*WAIT...1.5*WAIT secs between retrievals
(applies if more then 1 URL is to be retrieved)
--no-proxy explicitly turn off proxy
-Q, --quota=NUMBER set retrieval quota to NUMBER
--bind-address=ADDRESS bind to ADDRESS (hostname or IP) on local host
--limit-rate=RATE limit download rate to RATE
--no-dns-cache disable caching DNS lookups
--restrict-file-names=OS restrict chars in file names to ones OS allows
--ignore-case ignore case when matching files/directories
-4, --inet4-only connect only to IPv4 addresses
-6, --inet6-only connect only to IPv6 addresses
--prefer-family=FAMILY connect first to addresses of specified family,
one of IPv6, IPv4, or none
--user=USER set both ftp and http user to USER
--password=PASS set both ftp and http password to PASS
--ask-password prompt for passwords
--use-askpass=COMMAND specify credential handler for requesting
username and password. If no COMMAND is
specified the WGET_ASKPASS or the SSH_ASKPASS
environment variable is used.
--no-iri turn off IRI support
--local-encoding=ENC use ENC as the local encoding for IRIs
--remote-encoding=ENC use ENC as the default remote encoding
--unlink remove file before clobber
--xattr turn on storage of metadata in extended file attributes
Directories:
-nd, --no-directories don't create directories
-x, --force-directories force creation of directories
-nH, --no-host-directories don't create host directories
--protocol-directories use protocol name in directories
-P, --directory-prefix=PREFIX save files to PREFIX/..
--cut-dirs=NUMBER ignore NUMBER remote directory components
HTTP options:
--http-user=USER set http user to USER
--http-password=PASS set http password to PASS
--no-cache disallow server-cached data
--default-page=NAME change the default page name (normally
this is 'index.html'.)
-E, --adjust-extension save HTML/CSS documents with proper extensions
--ignore-length ignore 'Content-Length' header field
--header=STRING insert STRING among the headers
--compression=TYPE choose compression, one of auto, gzip and none. (default: none)
--max-redirect maximum redirections allowed per page
--proxy-user=USER set USER as proxy username
--proxy-password=PASS set PASS as proxy password
--referer=URL include 'Referer: URL' header in HTTP request
--save-headers save the HTTP headers to file
-U, --user-agent=AGENT identify as AGENT instead of Wget/VERSION
--no-http-keep-alive disable HTTP keep-alive (persistent connections)
--no-cookies don't use cookies
--load-cookies=FILE load cookies from FILE before session
--save-cookies=FILE save cookies to FILE after session
--keep-session-cookies load and save session (non-permanent) cookies
--post-data=STRING use the POST method; send STRING as the data
--post-file=FILE use the POST method; send contents of FILE
--method=HTTPMethod use method "HTTPMethod" in the request
--body-data=STRING send STRING as data. --method MUST be set
--body-file=FILE send contents of FILE. --method MUST be set
--content-disposition honor the Content-Disposition header when
choosing local file names (EXPERIMENTAL)
--content-on-error output the received content on server errors
--auth-no-challenge send Basic HTTP authentication information
without first waiting for the server's
challenge
HTTPS (SSL/TLS) options:
--secure-protocol=PR choose secure protocol, one of auto, SSLv2,
SSLv3, TLSv1, TLSv1_1, TLSv1_2 and PFS
--https-only only follow secure HTTPS links
--no-check-certificate don't validate the server's certificate
--certificate=FILE client certificate file
--certificate-type=TYPE client certificate type, PEM or DER
--private-key=FILE private key file
--private-key-type=TYPE private key type, PEM or DER
--ca-certificate=FILE file with the bundle of CAs
--ca-directory=DIR directory where hash list of CAs is stored
--crl-file=FILE file with bundle of CRLs
--pinnedpubkey=FILE/HASHES Public key (PEM/DER) file, or any number
of base64 encoded sha256 hashes preceded by
'sha256//' and separated by ';', to verify
peer against
--ciphers=STR Set the priority string (GnuTLS) or cipher list string (OpenSSL) directly.
Use with care. This option overrides --secure-protocol.
The format and syntax of this string depend on the specific SSL/TLS engine.
HSTS options:
--no-hsts disable HSTS
--hsts-file path of HSTS database (will override default)
FTP options:
--ftp-user=USER set ftp user to USER
--ftp-password=PASS set ftp password to PASS
--no-remove-listing don't remove '.listing' files
--no-glob turn off FTP file name globbing
--no-passive-ftp disable the "passive" transfer mode
--preserve-permissions preserve remote file permissions
--retr-symlinks when recursing, get linked-to files (not dir)
FTPS options:
--ftps-implicit use implicit FTPS (default port is 990)
--ftps-resume-ssl resume the SSL/TLS session started in the control connection when
opening a data connection
--ftps-clear-data-connection cipher the control channel only; all the data will be in plaintext
--ftps-fallback-to-ftp fall back to FTP if FTPS is not supported in the target server
WARC options:
--warc-file=FILENAME save request/response data to a .warc.gz file
--warc-header=STRING insert STRING into the warcinfo record
--warc-max-size=NUMBER set maximum size of WARC files to NUMBER
--warc-cdx write CDX index files
--warc-dedup=FILENAME do not store records listed in this CDX file
--no-warc-compression do not compress WARC files with GZIP
--no-warc-digests do not calculate SHA1 digests
--no-warc-keep-log do not store the log file in a WARC record
--warc-tempdir=DIRECTORY location for temporary files created by the
WARC writer
Recursive download:
-r, --recursive specify recursive download
-l, --level=NUMBER maximum recursion depth (inf or 0 for infinite)
--delete-after delete files locally after downloading them
-k, --convert-links make links in downloaded HTML or CSS point to
local files
--convert-file-only convert the file part of the URLs only (usually known as the basename)
--backups=N before writing file X, rotate up to N backup files
-K, --backup-converted before converting file X, back up as X.orig
-m, --mirror shortcut for -N -r -l inf --no-remove-listing
-p, --page-requisites get all images, etc. needed to display HTML page
--strict-comments turn on strict (SGML) handling of HTML comments
Recursive accept/reject:
-A, --accept=LIST comma-separated list of accepted extensions
-R, --reject=LIST comma-separated list of rejected extensions
--accept-regex=REGEX regex matching accepted URLs
--reject-regex=REGEX regex matching rejected URLs
--regex-type=TYPE regex type (posix|pcre)
-D, --domains=LIST comma-separated list of accepted domains
--exclude-domains=LIST comma-separated list of rejected domains
--follow-ftp follow FTP links from HTML documents
--follow-tags=LIST comma-separated list of followed HTML tags
--ignore-tags=LIST comma-separated list of ignored HTML tags
-H, --span-hosts go to foreign hosts when recursive
-L, --relative follow relative links only
-I, --include-directories=LIST list of allowed directories
--trust-server-names use the name specified by the redirection
URL's last component
-X, --exclude-directories=LIST list of excluded directories
-np, --no-parent don't ascend to the parent directory
Email bug reports, questions, discussions to <bug-wget@gnu.org>
and/or open issues at https://savannah.gnu.org/bugs/?func=additem&group=wget.
3.3 - ftp
Important - Si la commande ftp n'est pas installée sous RedHat 9, installez-le à l'aide de la commande dnf install ftp en tant que root.
La commande ftp est utilisée pour le transfert de fichiers. Une fois connecté, il convient d'utiliser la commande help pour afficher la liste des commandes disponibles :
[root@redhat9 ~]# ftp ftp> help Commands may be abbreviated. Commands are: ! debug mdir sendport site $ dir mget put size account disconnect mkdir pwd status append exit mls quit struct ascii form mode quote system bell get modtime recv sunique binary glob mput reget tenex bye hash newer rstatus tick case help nmap rhelp trace cd idle nlist rename type cdup image ntrans reset user chmod lcd open restart umask close ls prompt rmdir verbose cr macdef passive runique ? delete mdelete proxy send ftp>
Le caractère ! permet d'exécuter une commande sur la machine cliente
ftp> !pwd /root
Pour transférer un fichier vers le serveur, il convient d'utiliser la commande put :
ftp> put nom_fichier_local nom_fichier_distant
Vous pouvez également transférer plusieurs fichiers à la fois grâce à la commande mput. Dans ce cas précis, il convient de saisir la commande suivante:
ftp> mput nom*.*
Pour transférer un fichier du serveur, il convient d'utiliser la commande get :
ftp> get nom_fichier
Vous pouvez également transférer plusieurs fichiers à la fois grâce à la commande mget ( voir la commande mput ci-dessus ).
Pour supprimer un fichier sur le serveur, il convient d'utiliser la commande del :
ftp> del nom_fichier
Pour fermer la session, il convient d'utiliser la commande quit :
ftp> quit [root@redhat9 ~]#
3.4 - SSH
Présentation
La commande ssh est le successeur et la remplaçante de la commande rlogin. Il permet d'établir des connexions sécurisées avec une machine distante. SSH comporte cinq acteurs :
- Le serveur SSH
- le démon sshd, qui s'occupe des authentifications et autorisations des clients,
- Le client SSH
- ssh ou scp, qui assure la connexion et le dialogue avec le serveur,
- La session qui représente la connexion courante et qui commence juste après l'authentification réussie,
- Les clefs
- Couple de clef utilisateur asymétriques et persistantes qui assurent l'identité d'un utilisateur et qui sont stockés sur disque dur,
- Clef hôte asymétrique et persistante garantissant l'identité du serveur er qui est conservé sur disque dur
- Clef serveur asymétrique et temporaire utilisée par le protocole SSH1 qui sert au chiffrement de la clé de session,
- Clef de session symétrique qui est générée aléatoirement et qui permet le chiiffrement de la communication entre le client et le serveur. Elle est détruite en fin de session. SSH-1 utilise une seule clef tandis que SSH-2 utilise une clef par direction de la communication,
- La base de données des hôtes connus qui stocke les clés des connexions précédentes.
SSH fonctionne de la manière suivante pour la la mise en place d'un canal sécurisé:
- Le client contacte le serveur sur son port 22,
- Les client et le serveur échangent leur version de SSH. En cas de non-compatibilité de versions, l'un des deux met fin au processus,
- Le serveur SSH s'identifie auprès du client en lui fournissant :
- Sa clé hôte,
- Sa clé serveur,
- Une séquence aléatoire de huit octets à inclure dans les futures réponses du client,
- Une liste de méthodes de chiffrage, compression et authentification,
- Le client et le serveur produisent un identifiant identique, un haché MD5 long de 128 bits contenant la clé hôte, la clé serveur et la séquence aléatoire,
- Le client génère sa clé de session symétrique et la chiffre deux fois de suite, une fois avec la clé hôte du serveur et la deuxième fois avec la clé serveur. Le client envoie cette clé au serveur accompagnée de la séquence aléatoire et un choix d'algorithmes supportés,
- Le serveur déchiffre la clé de session,
- Le client et le serveur mettent en place le canal sécurisé.
SSH-1
SSH-1 utilise une paire de clefs de type RSA1. Il assure l'intégrité des données par une Contrôle de Redondance Cyclique (CRC) et est un bloc dit monolithique.
Afin de s'identifier, le client essaie chacune des six méthodes suivantes :
- Kerberos,
- Rhosts,
- RhostsRSA,
- Par clef asymétrique,
- TIS,
- Par mot de passe.
SSH-2
SSH-2 utilise DSA ou RSA. Il assure l'intégrité des données par l'algorithme HMAC. SSH-2 est organisé en trois couches :
- SSH-TRANS – Transport Layer Protocol,
- SSH-AUTH – Authentification Protocol,
- SSH-CONN – Connection Protocol.
SSH-2 diffère de SSH-1 essentiellement dans la phase authentification.
Trois méthodes d'authentification :
- Par clef asymétrique,
- Identique à SSH-1 sauf avec l'algorithme DSA,
- RhostsRSA,
- Par mot de passe.
Options de la commande
Les options de cette commande sont :
[root@redhat9 ~]# ssh --help
unknown option -- -
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]
[-b bind_address] [-c cipher_spec] [-D [bind_address:]port]
[-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]
[-i identity_file] [-J [user@]host[:port]] [-L address]
[-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]
[-Q query_option] [-R address] [-S ctl_path] [-W host:port]
[-w local_tun[:remote_tun]] destination [command]
Authentification par mot de passe
L'utilisateur fournit un mot de passe au client ssh. Le client ssh le transmet de façon sécurisée au serveur ssh puis le serveur vérifie le mot de passe et l'accepte ou non.
Avantage:
- Aucune configuration de clef asymétrique n'est nécessaire.
Inconvénients:
- L'utilisateur doit fournir à chaque connexion un identifiant et un mot de passe,
- Moins sécurisé qu'un système par clef asymétrique.
Authentification par clef asymétrique
- Le client envoie au serveur une requête d'authentification par clé asymétrique qui contient le module de la clé à utiliser,
- Le serveur recherche une correspondance pour ce module dans le fichier des clés autorisés ~/.ssh/authorized_keys,
- Dans le cas où une correspondance n'est pas trouvée, le serveur met fin à la communication,
- Dans le cas contraire le serveur génère une chaîne aléatoire de 256 bits appelée un challenge et la chiffre avec la clé publique du client,
- Le client reçoit le challenge et le décrypte avec la partie privée de sa clé. Il combine le challenge avec l'identifiant de session et chiffre le résultat. Ensuite il envoie le résultat chiffré au serveur.
- Le serveur génère le même haché et le compare avec celui reçu du client. Si les deux hachés sont identiques, l'authentification est réussie.
Configuration du Serveur
La configuration du serveur s'effectue dans le fichier /etc/ssh/sshd_config :
[root@redhat9 ~]# cat /etc/ssh/sshd_config # $OpenBSD: sshd_config,v 1.104 2021/07/02 05:11:21 dtucker Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options override the # default value. # To modify the system-wide sshd configuration, create a *.conf file under # /etc/ssh/sshd_config.d/ which will be automatically included below Include /etc/ssh/sshd_config.d/*.conf # If you want to change the port on a SELinux system, you have to tell # SELinux about this change. # semanage port -a -t ssh_port_t -p tcp #PORTNUMBER # #Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: #HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_ecdsa_key #HostKey /etc/ssh/ssh_host_ed25519_key # Ciphers and keying #RekeyLimit default none # Logging #SyslogFacility AUTH #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin prohibit-password #StrictModes yes #MaxAuthTries 6 #MaxSessions 10 #PubkeyAuthentication yes # The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2 # but this is overridden so installations will only check .ssh/authorized_keys AuthorizedKeysFile .ssh/authorized_keys #AuthorizedPrincipalsFile none #AuthorizedKeysCommand none #AuthorizedKeysCommandUser nobody # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no # Change to no to disable s/key passwords #KbdInteractiveAuthentication yes # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no #KerberosUseKuserok yes # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes #GSSAPIStrictAcceptorCheck yes #GSSAPIKeyExchange no #GSSAPIEnablek5users no # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the KbdInteractiveAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via KbdInteractiveAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and KbdInteractiveAuthentication to 'no'. # WARNING: 'UsePAM no' is not supported in RHEL and may cause several # problems. #UsePAM no #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no #X11Forwarding no #X11DisplayOffset 10 #X11UseLocalhost yes #PermitTTY yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #UseDNS no #PidFile /var/run/sshd.pid #MaxStartups 10:30:100 #PermitTunnel no #ChrootDirectory none #VersionAddendum none # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/libexec/openssh/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # PermitTTY no # ForceCommand cvs server
Pour ôter les lignes de commentaires dans ce fichier, utilisez la commande suivante :
[root@redhat9 ~]# cd /tmp ; grep -E -v '^(#|$)' /etc/ssh/sshd_config > sshd_config [root@redhat9 tmp]# cat sshd_config Include /etc/ssh/sshd_config.d/*.conf AuthorizedKeysFile .ssh/authorized_keys Subsystem sftp /usr/libexec/openssh/sftp-server
Pour sécuriser le serveur ssh, ajoutez ou modifiez les directives suivantes :
AllowGroups adm Banner /etc/issue.net HostbasedAuthentication no IgnoreRhosts yes LoginGraceTime 60 LogLevel INFO PermitEmptyPasswords no PermitRootLogin no PrintLastLog yes Protocol 2 StrictModes yes X11Forwarding no
Votre fichier ressemblera à celui-ci :
[root@redhat9 tmp]# vi sshd_config [root@redhat9 tmp]# cat sshd_config AllowGroups adm Banner /etc/issue.net HostbasedAuthentication no IgnoreRhosts yes LoginGraceTime 60 LogLevel INFO PermitEmptyPasswords no PermitRootLogin no PrintLastLog yes Protocol 2 StrictModes yes X11Forwarding no Include /etc/ssh/sshd_config.d/*.conf AuthorizedKeysFile .ssh/authorized_keys Subsystem sftp /usr/libexec/openssh/sftp-server
Renommez le fichier /etc/ssh/sshd_config en /etc/ssh/sshd_config.old :
[root@redhat9 tmp]# cp /etc/ssh/sshd_config /etc/ssh/sshd_config.old
Copiez le fichier /tmp/sshd_config vers /etc/ssh/ :
[root@redhat9 tmp]# cp /tmp/sshd_config /etc/ssh cp: overwrite '/etc/ssh/sshd_config'? y
Redémarrez le service sshd :
[root@redhat9 tmp]# systemctl restart sshd
[root@redhat9 tmp]# systemctl status sshd
● sshd.service - OpenSSH server daemon
Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; preset: enabled)
Active: active (running) since Sun 2024-09-29 14:06:49 CEST; 9s ago
Docs: man:sshd(8)
man:sshd_config(5)
Main PID: 5560 (sshd)
Tasks: 1 (limit: 48800)
Memory: 1.4M
CPU: 13ms
CGroup: /system.slice/sshd.service
└─5560 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"
Sep 29 14:06:49 redhat9.ittraining.loc systemd[1]: Starting OpenSSH server daemon...
Sep 29 14:06:49 redhat9.ittraining.loc sshd[5560]: Server listening on 0.0.0.0 port 22.
Sep 29 14:06:49 redhat9.ittraining.loc sshd[5560]: Server listening on :: port 22.
Sep 29 14:06:49 redhat9.ittraining.loc systemd[1]: Started OpenSSH server daemon.
Mettez l'utilisateur trainee dans le groupe adm :
[root@redhat9 tmp]# groups trainee trainee : trainee [root@redhat9 tmp]# usermod -aG adm trainee [root@redhat9 tmp]# groups trainee trainee : trainee adm
Pour générer les clefs du serveur, saisissez la commande suivante en tant que root. Notez que la passphrase doit être vide.
[root@redhat9 tmp]# ssh-keygen -t dsa Generating public/private dsa key pair. Enter file in which to save the key (/root/.ssh/id_dsa): /etc/ssh/ssh_host_dsa_key Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /etc/ssh/ssh_host_dsa_key Your public key has been saved in /etc/ssh/ssh_host_dsa_key.pub The key fingerprint is: SHA256:VWOX1JHwvNZHo8kC6OLgKXypZI97W56JBiKwc9YjFpk root@redhat9.ittraining.loc The key's randomart image is: +---[DSA 1024]----+ | +o++o| | . o o+..| | o . .. +.| |. E . .. . o.+| |.. + . .S . + oo| |*.* B . . . .| |oX.* + | |o *o+ o | | +++.+ | +----[SHA256]-----+
De la même façon, il est possible de générer les clefs au format RSA, ECDSA et ED25519 :
[root@redhat9 tmp]# ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): /etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_rsa_key already exists. Overwrite (y/n)? y Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /etc/ssh/ssh_host_rsa_key Your public key has been saved in /etc/ssh/ssh_host_rsa_key.pub The key fingerprint is: SHA256:SjQBVxLP5mtWmsHUWN0j1FvgokkEmKbEftzWc1ZlrAM root@redhat9.ittraining.loc The key's randomart image is: +---[RSA 3072]----+ | ...==o.oo.o.+o| | o.+= = E.=.o| | o +o.*.o .+.= | | o.o*o.ooo.+ | | ...S ++ . | | . . * | | . * | | o | | | +----[SHA256]-----+ [root@redhat9 tmp]# ssh-keygen -t ecdsa Generating public/private ecdsa key pair. Enter file in which to save the key (/root/.ssh/id_ecdsa): /etc/ssh/ssh_host_ecdsa_key /etc/ssh/ssh_host_ecdsa_key already exists. Overwrite (y/n)? y Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /etc/ssh/ssh_host_ecdsa_key Your public key has been saved in /etc/ssh/ssh_host_ecdsa_key.pub The key fingerprint is: SHA256:auaDgRcvbqpC5SkGadt7AizXVta2A8w5hYwVgUPXNlc root@redhat9.ittraining.loc The key's randomart image is: +---[ECDSA 256]---+ | ..=== .E | | +.o = . | | . + = o | |o. .. O o | |+ =o.= +S. | |.Bo+* ..o | |+.o+.++ . | |. o+=. | |o..oo .. | +----[SHA256]-----+ [root@redhat9 tmp]# ssh-keygen -t ed25519 Generating public/private ed25519 key pair. Enter file in which to save the key (/root/.ssh/id_ed25519): /etc/ssh/ssh_host_ed25519_key /etc/ssh/ssh_host_ed25519_key already exists. Overwrite (y/n)? y Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /etc/ssh/ssh_host_ed25519_key Your public key has been saved in /etc/ssh/ssh_host_ed25519_key.pub The key fingerprint is: SHA256:UwUjA5Ln700GWzhNxvIvdNafLOhD1/hdrMigOvARQwI root@redhat9.ittraining.loc The key's randomart image is: +--[ED25519 256]--+ | E.....o.o.. | | o.o .o+o | | = B. . | | + +.= o . | | +S* +. +o.| | . . o.=o.+ ++| | o o =o+..o.o| | o o .oo ...| | .o . | +----[SHA256]-----+
Les clefs publiques générées possèdent l'extension .pub. Les clefs privées n'ont pas d'extension :
[root@redhat9 tmp]# ls /etc/ssh moduli ssh_config.d sshd_config.d ssh_host_dsa_key ssh_host_ecdsa_key ssh_host_ed25519_key ssh_host_rsa_key ssh_config sshd_config sshd_config.old ssh_host_dsa_key.pub ssh_host_ecdsa_key.pub ssh_host_ed25519_key.pub ssh_host_rsa_key.pub
Re-démarrez ensuite le service sshd :
[root@redhat9 tmp]# systemctl restart sshd.service
[root@redhat9 tmp]# systemctl status sshd.service
● sshd.service - OpenSSH server daemon
Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; preset: enabled)
Active: active (running) since Sun 2024-09-29 14:14:14 CEST; 13s ago
Docs: man:sshd(8)
man:sshd_config(5)
Main PID: 5583 (sshd)
Tasks: 1 (limit: 48800)
Memory: 1.3M
CPU: 12ms
CGroup: /system.slice/sshd.service
└─5583 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"
Sep 29 14:14:14 redhat9.ittraining.loc systemd[1]: sshd.service: Deactivated successfully.
Sep 29 14:14:14 redhat9.ittraining.loc sshd[5583]: Server listening on 0.0.0.0 port 22.
Sep 29 14:14:14 redhat9.ittraining.loc systemd[1]: Stopped OpenSSH server daemon.
Sep 29 14:14:14 redhat9.ittraining.loc sshd[5583]: Server listening on :: port 22.
Sep 29 14:14:14 redhat9.ittraining.loc systemd[1]: Starting OpenSSH server daemon...
Sep 29 14:14:14 redhat9.ittraining.loc systemd[1]: Started OpenSSH server daemon.
Configuration du Client
Saisissez maintenant les commandes suivantes en tant que trainee :
Important - Lors de la génération des clefs, la passphrase doit être vide.
[root@redhat9 tmp]# exit logout [trainee@redhat9 ~]$ ssh-keygen -t dsa Generating public/private dsa key pair. Enter file in which to save the key (/home/trainee/.ssh/id_dsa): Created directory '/home/trainee/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/trainee/.ssh/id_dsa Your public key has been saved in /home/trainee/.ssh/id_dsa.pub The key fingerprint is: SHA256:TT4VSKqep7i/5t6FoPSQ88LmTo3eLRBBFxz3Cz2Kxi4 trainee@redhat9.ittraining.loc The key's randomart image is: +---[DSA 1024]----+ | ...+o..... | | .... +. . | | . o = . | | .o o * + | | =.* S = | | o.% o . . | | E.B o . | | = =o= . | | .**Boo | +----[SHA256]-----+ [trainee@redhat9 ~]$ ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/trainee/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/trainee/.ssh/id_rsa Your public key has been saved in /home/trainee/.ssh/id_rsa.pub The key fingerprint is: SHA256:75jUyGd9zw6fA5Z2KIZAacp+0b5KLeWpOONItt/4Z9k trainee@redhat9.ittraining.loc The key's randomart image is: +---[RSA 3072]----+ | . | | + | | . + . | | o o . | | . S.. o | | . o+*.+ * . | | o .o++X = = | | o oo=.o@ E . *.| | oo=+=* . o*| +----[SHA256]-----+ [trainee@redhat9 ~]$ ssh-keygen -t ecdsa Generating public/private ecdsa key pair. Enter file in which to save the key (/home/trainee/.ssh/id_ecdsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/trainee/.ssh/id_ecdsa Your public key has been saved in /home/trainee/.ssh/id_ecdsa.pub The key fingerprint is: SHA256:xjl9G3ycaF3s9cuyCqHhPvUWyN1qzBGxJtZwFAFeRvw trainee@redhat9.ittraining.loc The key's randomart image is: +---[ECDSA 256]---+ | .=Bo | | ..o+ . | | .+ + +| | . = * E +o| | .S.* O = o| | ..o=.* =. .| | o..+ =. o | | .. .B o | | .. o... | +----[SHA256]-----+ [trainee@redhat9 ~]$ ssh-keygen -t ed25519 Generating public/private ed25519 key pair. Enter file in which to save the key (/home/trainee/.ssh/id_ed25519): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/trainee/.ssh/id_ed25519 Your public key has been saved in /home/trainee/.ssh/id_ed25519.pub The key fingerprint is: SHA256:qtFzx7O0swNGsRoP9Cy+cISURCvWYpANMn1WtljZ8WQ trainee@redhat9.ittraining.loc The key's randomart image is: +--[ED25519 256]--+ |== ooo+o..E | |ooo.==o.o+ | | =++o.o o. | | o o. = = | | o BS | | ..+.+. | | .o+o..= | | o.o oo+ | | . ++ | +----[SHA256]-----+
Les clés générées seront placées dans le répertoire ~/.ssh/ :
[trainee@redhat9 ~]$ ls .ssh id_dsa id_dsa.pub id_ecdsa id_ecdsa.pub id_ed25519 id_ed25519.pub id_rsa id_rsa.pub
Tunnels SSH
Le protocole SSH peut être utilisé pour sécuriser les protocoles tels telnet, pop3 etc.. En effet, on peut créer un tunnel SSH dans lequel passe les communications du protocole non-sécurisé.
La commande pour créer un tunnel ssh prend la forme suivante :
ssh -N -f compte@hôte -Lport-local:localhost:port_distant
Dans votre cas, vous allez créer un tunnel dans votre propre vm entre le port 15023 et le port 23 :
[trainee@redhat9 ~]$ ssh -N -f trainee@localhost -L15023:localhost:23 The authenticity of host 'localhost (::1)' can't be established. ED25519 key fingerprint is SHA256:UwUjA5Ln700GWzhNxvIvdNafLOhD1/hdrMigOvARQwI. This key is not known by any other names Are you sure you want to continue connecting (yes/no/[fingerprint])? yes Warning: Permanently added 'localhost' (ED25519) to the list of known hosts. \S Kernel \r on an \m trainee@localhost's password: trainee
Installez maintenant le serveur telnet :
[trainee@redhat9 ~]$ su - Password: [root@redhat9 ~]# dnf install telnet-server Updating Subscription Management repositories. Last metadata expiration check: 3:26:47 ago on Sun 29 Sep 2024 10:52:14 AM CEST. Dependencies resolved. ================================================================================================================================================================================================================== Package Architecture Version Repository Size ================================================================================================================================================================================================================== Installing: telnet-server x86_64 1:0.17-85.el9 rhel-9-for-x86_64-appstream-rpms 41 k Transaction Summary ================================================================================================================================================================================================================== Install 1 Package Total download size: 41 k Installed size: 58 k Is this ok [y/N]: y Downloading Packages: telnet-server-0.17-85.el9.x86_64.rpm 145 kB/s | 41 kB 00:00 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Total 144 kB/s | 41 kB 00:00 Running transaction check Transaction check succeeded. Running transaction test Transaction test succeeded. Running transaction Preparing : 1/1 Installing : telnet-server-1:0.17-85.el9.x86_64 1/1 Running scriptlet: telnet-server-1:0.17-85.el9.x86_64 1/1 Verifying : telnet-server-1:0.17-85.el9.x86_64 1/1 Installed products updated. Installed: telnet-server-1:0.17-85.el9.x86_64 Complete!
Telnet n'est ni démarré ni activé. Il convient donc de le démarrer et de l'activer :
[root@redhat9 ~]# systemctl status telnet.socket
○ telnet.socket - Telnet Server Activation Socket
Loaded: loaded (/usr/lib/systemd/system/telnet.socket; disabled; preset: disabled)
Active: inactive (dead)
Docs: man:telnetd(8)
Listen: [::]:23 (Stream)
Accepted: 0; Connected: 0;
[root@redhat9 ~]# systemctl start telnet.socket
[root@redhat9 ~]# systemctl status telnet.socket
● telnet.socket - Telnet Server Activation Socket
Loaded: loaded (/usr/lib/systemd/system/telnet.socket; disabled; preset: disabled)
Active: active (listening) since Sun 2024-09-29 14:19:51 CEST; 13s ago
Until: Sun 2024-09-29 14:19:51 CEST; 13s ago
Docs: man:telnetd(8)
Listen: [::]:23 (Stream)
Accepted: 0; Connected: 0;
Tasks: 0 (limit: 48800)
Memory: 8.0K
CPU: 700us
CGroup: /system.slice/telnet.socket
Sep 29 14:19:51 redhat9.ittraining.loc systemd[1]: Listening on Telnet Server Activation Socket.
[root@redhat9 ~]# systemctl enable telnet.socket
Created symlink /etc/systemd/system/sockets.target.wants/telnet.socket → /usr/lib/systemd/system/telnet.socket.
Connectez-vous ensuite via telnet sur le port 15023, vous constaterez que votre connexion n'aboutit pas :
[root@redhat9 ~]# telnet localhost 15023 Trying ::1... Connected to localhost. Escape character is '^]'. Kernel 5.14.0-427.37.1.el9_4.x86_64 on an x86_64 redhat9 login: trainee Password: trainee Last login: Sun Sep 29 12:26:00 from 10.0.2.1 [trainee@redhat9 ~]$ whoami trainee [trainee@redhat9 ~]$ pwd /home/trainee
Important - Notez bien que votre communication telnet passe par le tunnel SSH.
3.5 - SCP
Présentation
La commande scp est le successeur et la remplaçante de la commande rcp de la famille des commandes remote. Il permet de faire des transferts sécurisés à partir d'une machine distante :
$ scp compte@numero_ip(nom_de_machine):/chemin_distant/fichier_distant /chemin_local/fichier_local
ou vers une machine distante :
$ scp /chemin_local/fichier_local compte@numero_ip(nom_de_machine):/chemin_distant/fichier_distant
Utilisation
Nous allons maintenant utiliser scp pour chercher un fichier sur le «serveur» :
Créez le fichier /home/trainee/scp_test :
[trainee@redhat9 ~]$ touch scp-test [trainee@redhat9 ~]$ exit logout Connection closed by foreign host. [root@redhat9 ~]#
Récupérez le fichier scp_test en utilisant scp :
[root@redhat9 ~]# scp trainee@127.0.0.1:/home/trainee/scp-test . The authenticity of host '127.0.0.1 (127.0.0.1)' can't be established. ED25519 key fingerprint is SHA256:UwUjA5Ln700GWzhNxvIvdNafLOhD1/hdrMigOvARQwI. This key is not known by any other names Are you sure you want to continue connecting (yes/no/[fingerprint])? yes Warning: Permanently added '127.0.0.1' (ED25519) to the list of known hosts. \S Kernel \r on an \m trainee@127.0.0.1's password: trainee [root@redhat9 ~]# ls -l total 2042944 -rw-------. 1 root root 1226 Oct 19 2023 anaconda-ks.cfg -rw-r--r--. 1 trainee trainee 2091941797 Oct 19 2023 ansible-automation-platform-setup-bundle-2.4-2.2-x86_64.tar.gz -rw-r--r--. 1 root root 64 Sep 27 08:24 device.map -rw-------. 1 root root 7118 Sep 27 08:24 grub.cfg drwxr-xr-x. 3 root root 21 Oct 19 2023 home -rw-r--r--. 1 root root 98 Sep 27 08:23 montages.list -rw-r--r--. 1 root root 2109 Sep 25 16:20 passwd -rw-r--r--. 1 root root 0 Sep 29 14:24 scp-test -rw-r--r--. 1 root root 457 Sep 27 08:22 structure.list -rw-r--r--. 1 root root 46 Sep 29 13:56 'wget_file.txt?rlkey=g8fgje9z8oeqgb4nd2g7x3wkx'
3.6 - Mise en Place des Clefs Asymétriques
Il convient maintenant de se connecter sur le «serveur» en utilisant ssh et vérifiez la présence du répertoire ~/.ssh :
[root@redhat9 ~]# ssh -l trainee 127.0.0.1 \S Kernel \r on an \m trainee@127.0.0.1's password: trainee Register this system with Red Hat Insights: insights-client --register Create an account or view all your systems at https://red.ht/insights-dashboard Last login: Sun Sep 29 14:21:21 2024 from localhost [trainee@redhat9 ~]$ ls -la | grep .ssh -rw-------. 1 trainee trainee 20 Sep 25 15:18 .lesshst drwx------. 2 trainee trainee 188 Sep 29 14:18 .ssh
Important - Si le dossier distant .ssh n'existe pas dans le répertoire personnel de l'utilisateur connecté, il faut le créer avec des permissions de 700. Dans votre cas, puisque votre machine joue le rôle de serveur et du client, le dossier /home/trainee/.ssh existe déjà.
Ensuite, il convient de transférer le fichier local .ssh/id_ecdsa.pub du «client» vers le «serveur» en le renommant en authorized_keys :
[trainee@redhat9 ~]$ exit
logout
Connection to 127.0.0.1 closed.
[root@redhat9 ~]# exit
logout
[trainee@redhat9 ~]$ scp .ssh/id_ecdsa.pub trainee@127.0.0.1:/home/trainee/.ssh/authorized_keys
The authenticity of host '127.0.0.1 (127.0.0.1)' can't be established.
ED25519 key fingerprint is SHA256:UwUjA5Ln700GWzhNxvIvdNafLOhD1/hdrMigOvARQwI.
This host key is known by the following other names/addresses:
~/.ssh/known_hosts:1: localhost
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '127.0.0.1' (ED25519) to the list of known hosts.
\S
Kernel \r on an \m
trainee@127.0.0.1's password: trainee
id_ecdsa.pub 100% 192 427.3KB/s 00:00
Connectez-vous via ssh :
[trainee@redhat9 ~]$ ssh -l trainee localhost \S Kernel \r on an \m Register this system with Red Hat Insights: insights-client --register Create an account or view all your systems at https://red.ht/insights-dashboard Last login: Sun Sep 29 14:26:20 2024 from 127.0.0.1 [trainee@redhat9 ~]$
Important - Lors de la connexion au serveur, l'authentification utilise le couple de clefs asymétrique au format ecdsa et aucun mot de passe n'est requis.
Insérez maintenant les clefs publiques restantes dans le fichier .ssh/authorized_keys :
[trainee@redhat9 ~]$ cd .ssh [trainee@redhat9 .ssh]$ ls authorized_keys id_dsa id_dsa.pub id_ecdsa id_ecdsa.pub id_ed25519 id_ed25519.pub id_rsa id_rsa.pub known_hosts known_hosts.old [trainee@redhat9 .ssh]$ cat authorized_keys ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBGJIMNJ1m+xIpYzfYwK7VpdCI9inhQx3wptO+z4Xsl3XYcb+WIXsEsJpKSyQnOv98HmfZVJWcqXaSBkE5mskFGI= trainee@redhat9.ittraining.loc [trainee@redhat9 .ssh]$ cat id_rsa.pub >> authorized_keys [trainee@redhat9 .ssh]$ cat id_dsa.pub >> authorized_keys [trainee@redhat9 .ssh]$ cat id_ed25519.pub >> authorized_keys [trainee@redhat9 .ssh]$ cat authorized_keys ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBGJIMNJ1m+xIpYzfYwK7VpdCI9inhQx3wptO+z4Xsl3XYcb+WIXsEsJpKSyQnOv98HmfZVJWcqXaSBkE5mskFGI= trainee@redhat9.ittraining.loc ssh-rsa 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 trainee@redhat9.ittraining.loc ssh-dss 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 trainee@redhat9.ittraining.loc ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKzhdX1reo1vStZd/lfAQ1Yjz7eo0qj7ir/f6jyGp4iG trainee@redhat9.ittraining.loc [trainee@redhat9 .ssh]$ exit logout Connection to localhost closed. [trainee@redhat9 ~]$
Copyright © 2024 Hugh Norris.
