RE: BFD LSP Ping

[Nitin Bahadur <nitinb at juniper.net>]

I'm not sure if the TTL check is mandatory/required for BFD MPLS.

Thanks
Nitin 

> -----Original Message-----
> From: rtg-bfd-bounces at ietf.org [mailto:rtg-bfd-bounces at ietf.org] On Behalf
> Of Vishwas Manral
> Sent: Wednesday, October 28, 2009 10:58 AM
> To: rtg-bfd at ietf.org
> Cc: Kireeti Kompella; Rahul Aggarwal
> Subject: BFD LSP Ping
> 
> Hi,
> 
> I noticed a basic issue with BFD LSP ping with a a TTL processing in a
> Uniform Model LSP.
> 
> The draft states that:
> 
> 
>    The BFD control packet sent by the ingress LSR MUST be a UDP packet
>    with a well known destination port 3784 [BFD-IP] and a source port
>    assigned by the sender as per the procedures in [BFD-IP].
> 
> A single hop session verifies the TTL is 255. However the TTL in the
> IP header is changed at the Egress before the IP header handling
> because we are using hte uniform model. I think the easiest and the
> best way for this would be to use Multihop sessions in both
> directions.
> 
> Do let me know if I am missing something?
> 
> Thanks,
> Vishwas