Re: Mirja Kühlewind's Discuss on draft-ietf-bfd-seamless-base-09: (with DISCUSS)

[Manav Bhatia <[e-mail]>]

Hi Mirja,

>
>
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
>
> As S-BFD has no initiation process anymore it is not guarenteed that the
> receiver/responder actually exists. That means that packets could float
> (uncontrolled) in the network or even outside of the adminstrative domain
> (e.g. due to configuration mistakes). From my point of view this document
> should recommend/require two things:
>
> 1) A maximum number of S-BFD packet that is allow to be send without
> getting a response (maybe leading to a local error report).
>
> 2) Egress filtering at the adminstrative border of the domain that uses
> S-BFD to make sure that no S-BFD packets leave the domain.
>
>
>
How different is this from having a regular BFD/OSPF/ISIS speaker
misconfigured to to peer with a router that it is not supposed to peer
with. In such cases OSPF/ISIS, etc will continue sending HELLOs. So why do
anything different for S-BFD.

Moreover, the whole idea of rate-limiting S-BFD packets is fundamentally
incorrect. Its possible that the SBFD peer that router is trying to send
S-BFD packets to may be down for some reason. In such cases you will NOT
receive a response. Its only when it comes up that you will get a response.

Am i missing something here?

Cheers, Manav