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

[Mark Smith <[e-mail]>]

On Tue, 17 Aug 2010 11:20:56 +0300 (EEST)
Pekka Savola <[e-mail]> wrote:

> Hi,
> 
> I changed the subject, because the original intent was lost in the 
> weeds.
> 
> On Mon, 16 Aug 2010, Olivier Vautrin wrote:
> > It is clear that there is one more action done on the packet with 
> > RFC4443. But this has no impact on shipping ASIC based routers. It 
> > is difficult to say though if some smaller routers could be 
> > impacted.
> 
> This, and what Ole Troan wrote on interface lookup, is interesting.
> 
> RFC4443 requires checking that destination address matches the subnet 
> prefix.  Is this the hot issue?
> 
> Note that pingpong-00 document did not have this requirement; the 
> specification was different (incoming/outgoing interface).  Does this 
> have different implications on the feasibility of implementation?
> 
> 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.
> 

Would that mechanism be described in -

RFC5881 - "Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6
(Single Hop)"

?

I'm aware of a proposal to use it for CPE to test for the
absence/presence of a remote BRAS, which in the case of PPP virtual
circuits, would avoid the BRAS control plane having to respond to LCP
Echo Requests. That's quite attractive with BRASes now being able to
carry multiple 10s of 1000s of subscribers.

Regards,
Mark.