Re: [Lsr] Multiple failures in Dynamic Flooding

"Les Ginsberg (ginsberg)" <ginsberg@cisco.com> Wed, 06 March 2019 18:29 UTC

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From: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
To: "tony.li@tony.li" <tony.li@tony.li>, Huaimo Chen <huaimo.chen@huawei.com>
CC: "lsr@ietf.org" <lsr@ietf.org>, "lsr-ads@ietf.org" <lsr-ads@ietf.org>, Christian Hopps <chopps@chopps.org>, "lsr-chairs@ietf.org" <lsr-chairs@ietf.org>
Thread-Topic: [Lsr] Multiple failures in Dynamic Flooding
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Date: Wed, 6 Mar 2019 18:29:47 +0000
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Subject: Re: [Lsr] Multiple failures in Dynamic Flooding
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It takes too long when Hello packet is lost. Repairing split flooding topology needs to be fast.


Fortunately, lost hello packets are a relatively rare occurrence.  While repairing the flooding topology needs to be done expediently, attempting to do so and triggering a cascade failure of the network is counter-productive. Given this alternative, a bit of extra delay when adding a new system to the network, or trying to recover from multiple failures seems wise. Rushing and making things worse does not.  The first
priority must remain network stability.



[Les:] Just to put this minor issue to rest…
It would also be possible for the node making the temporary flooding request to send hellos at a faster rate (say once a second rather than once every 10 seconds) until it sees that the neighbor is sending LSP/SNP updates.
This just isn’t a significant issue.

   Les