RE: draft-ietf-ipngwg-p2p-pingpong-00.txt vs RFC4443

[Olivier Vautrin <[e-mail]>]

> 
> > FWIW, "Packet may be forwarded back on the received interface" is
> > actually, AFAIK, used in certain PE routerscenarios where you ping
> > yourself over a p2p link.
> 
> Is the echo request/response really forwarded back on the received
> interface? (isn't the *response* that is forwarded back on the received
> interface?)
> 

No. Again, There could be cases where packet needs to be sent back onto point-to-point links from which they were received.  For example, an LER (Label Edge Router) could just forward the packet solely based on its label without IP resolution.  In this case, if the destination was the LER's egress interface, then the downstream router would do an IP lookup and sent back the packet to its interface (it could be a ping to the LSR egress interface for example).

If the downstream router was using RFC4443, it would break the ping (in this example).

/Olivier