Sous linux
Lancer la commande suivante
ping -M do -s 1500 adresse_d_une_machine
PING www.celeste.fr (83.142.144.99) 1500(1528) bytes of data. From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492) From webaps.airaps.local (172.16.43.103) icmp_seq=1 Frag needed and DF set (mtu = 1492)
On peut noter le mtu = 1492
Sous FreeBSD se sera la commande
ping -D -s 1500 adresse_ip ping: sendto: Message too long
On refait alors un test avec cette valeur - 28 (je sais plus pourquoi le 28 …
ping -M do -s 1464 www.celeste.fr
et ca marche ;)
PING www.celeste.fr (83.142.144.99) 1464(1492) bytes of data. 1472 bytes from www2.celeste.fr (83.142.144.99): icmp_seq=1 ttl=59 time=75.5 ms 1472 bytes from www2.celeste.fr (83.142.144.99): icmp_seq=2 ttl=59 time=75.9 ms 1472 bytes from www2.celeste.fr (83.142.144.99): icmp_seq=3 ttl=59 time=76.3 ms --- www.celeste.fr ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 75.543/75.936/76.324/0.390 ms
Un petit coup de
ifconfig eth0 mtu 1492
Et voila, votre interface est maintenant réglé, penser à modifier votre fichier /etc/network/interfaces pour que cette valeur de mtu soit prise en compte lors du redémarrage de la machine.