trovato il problema mancava encapsulation aal5snap sulla interfaccia ATM

poi ho settato MTU = 1492 e MSS a 1452

Ecco un ping direi che va abbastanza bene

bash-2.05b# ping maya.ngi.it
PING maya.ngi.it (194.185.88.3) 56(84) bytes of data.
64 bytes from maya.ngi.it (194.185.88.3): icmp_seq=2 ttl=245 time=44.5 ms
64 bytes from maya.ngi.it (194.185.88.3): icmp_seq=3 ttl=245 time=46.8 ms
64 bytes from maya.ngi.it (194.185.88.3): icmp_seq=4 ttl=245 time=45.4 ms
64 bytes from maya.ngi.it (194.185.88.3): icmp_seq=5 ttl=245 time=42.9 ms