Свежая система debian sid:
localhost:/# ping localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
^C
--- localhost ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2014ms
localhost:/# ping ya.ru
PING ya.ru (213.180.204.8) 56(84) bytes of data.
64 bytes from ya.ru (213.180.204.8): icmp_seq=1 ttl=55 time=27.0 ms
localhost:/# ip rule show
0: from all lookup local
32766: from all lookup main
32767: from all lookup default
Что забыл разрешить?