reseau en panne?

[J Bond 0.07]

Bonjour,
Le ping violette depuis moustique ok:
mb at moustique:~$ ping violette
PING violette (192.168.88.3) 56(84) bytes of data.
64 bytes from violette (192.168.88.3): icmp_seq=1 ttl=64 time=0.090 ms
64 bytes from violette (192.168.88.3): icmp_seq=2 ttl=64 time=0.080 ms
64 bytes from violette (192.168.88.3): icmp_seq=3 ttl=64 time=0.079 ms
64 bytes from violette (192.168.88.3): icmp_seq=4 ttl=64 time=0.085 ms
64 bytes from violette (192.168.88.3): icmp_seq=5 ttl=64 time=0.087 ms
64 bytes from violette (192.168.88.3): icmp_seq=6 ttl=64 time=0.081 ms

--- violette ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 4997ms
rtt min/avg/max/mdev = 0.079/0.083/0.090/0.011 ms
mb at moustique:~$

Mais le ping moustique depuis violette, pas ok :

sudo /etc/init.d/networking restart
.....reconfiguring ubterfaces
							[ok]

mb at violette: ping moustique
moustique(192.168.88.1)
violette(192.168.88.3)..Destination host unreachable
  violette(192.168.88.3)..Destination host unreachable
  violette(192.168.88.3)..Destination host unreachable
  violette(192.168.88.3)..Destination host unreachable
violette(192.168.88.3)..Destination host unreachable
  violette(192.168.88.3)..Destination host unreachable
  violette(192.168.88.3)..Destination host unreachable
  violette(192.168.88.3)..Destination host unreachable


Le 1er paquet passe et atteint le serveur et le serveur de noms.
Mais tous les paquets suivants échouent!...

Si qqun avait une idée?