Subject: Re: [bess] REG: draft-mohanty-bess-evpn-df-election-02

From: Tony Przygienda <[email-masked]>
Date: Mon, 23 Nov 2015 20:19:19 -0800

> 1. When a new PE comes in the MH segment.
> [Satya] Yes, New PE needs to wait for 3 sec. According to RFC 7438, the
> receiving PEs also need to wait for 3 secs. But, ideally, a PE that is
> going from DF to non-DF or non-DF to non-DF should become the non-DF right
> away. Only the PE that is going DF really needs to wait for 3 secs. This is
> not explicitly spelled out in the draft but we are thinking along these
> lines.

Actually, the only reason to give up DF is if a new ES route is received
and then 3 secs is necessary for e'one. If a ES is lost, no wait time is
necessary on re-election (i.e. DFs can assume DF immediately or give up DF
immediately). Small window of ES route loss being realized by all peers is
of course here (but we assume that is happening very fast in today's
deployments). FSM in the draft shows that. Are any improvements needed
there ? All those questions should be answered by reference FSM in the
draft already so it's worth improving it (I see this question 3rd time or
so already ?)

thanks

-- tony

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