NATs (NAT-PTs) are defined to translate TCP and UDP but usually can translate the ICMP echo service as known as 'ping'. It is an (ab)use of the ID field of ICMP echo/echo reply packets which is handled the same way than the TCP/UDP source port.
So in the real world 'ping' works at the same place than TCP or UDP, at least when it is about NATs (some firewalls blindly drop all ICMPs, some stacks fail to implement ICMP, etc, but this has nothing to do with NATs), but this statement applies to the poor guy behind a NAT. The issue is in the "Internet -> poor guy behind a NAT" way. In fact it could work exactly the same way than for a TCP/UDP server behind a NAT, but no standard 'ping' command provides a way to give the ID to use, so to make it to work you need a modified ping (I can provide a modified source for Linux if someone wants to experiment). Regards [email protected] PS: I put this here because it seems someone claims ping doesn't work with 4rd. _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
