Verificação da conectividade entre hosts §

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O comando ping testa a conectividade. O comando continuará sendo executado até você pressionar Ctrl+c, a menos que sejam indicadas opções para limitar o número de pacotes enviados.

[user@host ~]$ ping -c3 192.0.2.254
PING 192.0.2.1 (192.0.2.254) 56(84) bytes of data.
64 bytes from 192.0.2.254: icmp_seq=1 ttl=64 time=4.33 ms
64 bytes from 192.0.2.254: icmp_seq=2 ttl=64 time=3.48 ms
64 bytes from 192.0.2.254: icmp_seq=3 ttl=64 time=6.83 ms
 
--- 192.0.2.254 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 3.485/4.885/6.837/1.424 ms

O comando ping6 é a versão IPv6 do comando ping no Red Hat Enterprise Linux. A diferença entre esses comandos é que o comando ping6 se comunica por IPv6 e recebe endereços IPv6.

[user@host ~]$ ping6 2001:db8:0:1::1
PING 2001:db8:0:1::1(2001:db8:0:1::1) 56 data bytes
64 bytes from 2001:db8:0:1::1: icmp_seq=1 ttl=64 time=18.4 ms
64 bytes from 2001:db8:0:1::1: icmp_seq=2 ttl=64 time=0.178 ms
64 bytes from 2001:db8:0:1::1: icmp_seq=3 ttl=64 time=0.180 ms
^C
--- 2001:db8:0:1::1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2001ms
rtt min/avg/max/mdev = 0.178/6.272/18.458/8.616 ms
[user@host ~]$

Quando você faz ping dos endereços link-local e do grupo multicast link-local para todos os nós (ff02::1), a interface de rede a ser usada deve ser explicitamente especificada com um identificador de zona de escopo (como ff02::1%ens3). Se essa interface de rede for omitida, o erro connect: Invalid argument será exibido.

Você pode usar o comando ping6 ff02::1 para encontrar outros nós IPv6 na rede local.

[user@host ~]$ ping6 ff02::1%ens4
PING ff02::1%ens4(ff02::1) 56 data bytes
64 bytes from fe80::78cf:7fff:fed2:f97b: icmp_seq=1 ttl=64 time=22.7 ms
64 bytes from fe80::f482:dbff:fe25:6a9f: icmp_seq=1 ttl=64 time=30.1 ms (DUP!)
64 bytes from fe80::78cf:7fff:fed2:f97b: icmp_seq=2 ttl=64 time=0.183 ms
64 bytes from fe80::f482:dbff:fe25:6a9f: icmp_seq=2 ttl=64 time=0.231 ms (DUP!)
^C
--- ff02::1%ens4 ping statistics ---
2 packets transmitted, 2 received, +2 duplicates, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.183/13.320/30.158/13.374 ms
[user@host ~]$
[user@host ~]$ ping6 -c 1 fe80::f482:dbff:fe25:6a9f%ens4
PING fe80::f482:dbff:fe25:6a9f%ens4(fe80::f482:dbff:fe25:6a9f) 56 data bytes
64 bytes from fe80::f482:dbff:fe25:6a9f: icmp_seq=1 ttl=64 time=22.9 ms
 
--- fe80::f482:dbff:fe25:6a9f%ens4 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 22.903/22.903/22.903/0.000 ms

Os endereços link-local IPv6 podem ser usados por outros hosts no mesmo link, como endereços normais.

[user@host ~]$ ssh fe80::f482:dbff:fe25:6a9f%ens4
user@fe80::f482:dbff:fe25:6a9f%ens4's password:
Last login: Thu Jun  5 15:20:10 2014 from host.example.com
[user@server ~]$

Referências §

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• Red Hat System Administration I