Re: Graceful restart comment

[Jeffrey Haas <[e-mail]>]

On Mon, Apr 29, 2002 at 01:58:04PM -0700, Pedro Roque Marques wrote:
> If you have errors in a PDU the best thing to do is to tear down the
> session not to selectivly ignore bits... if you can't trust your peer
> to format updates correctly then you can't trust any of the nlri that
> it has sent you.

Pedro,

Turn your wayback machine to the IDR list when we had the leaking
confederation segments incident killing parts of the Internet. :-)

The specific circumstances I have in mind are where we have a well-formed
packet, but the information is semantically incorrect, discard the
PDU.

> Accepting bad routing information is usually much harder to debug than
> not accepting information...

Hence the reason for telling your peer that you're doing this.

Can you think of circumstances where your implementation will drop
an update where it doesn't drop the peering session?

> I can't think of any scenario where it is reasonable to discard
> packets from the neighbor while maintaining the session up... if your
> neighbor is sending you packets for an NLRI that it hasn't negociated,
> chances are that there is something else wrong with it.

RFC 2858, section 6, paragraph 1. :-)

Mind you, I don't really have a problem with the portion I just cited,
but implementing that without having dynamic capabilities nor 
some sort of informational pushback is asking for your OAM people to
put your head on a plate. :-)

>   Pedro.

-- 
Jeff Haas 
NextHop Technologies