Soliciting your opinions on Internet routing: A survey on BGP convergence

Jakob Heitz (jheitz) jheitz at cisco.com
Tue Jan 10 19:51:57 UTC 2017


Hi Baldur,

Have you tried graceful shutdown?
You need redundant links, but not to the same transit.
https://tools.ietf.org/html/draft-ietf-grow-bgp-gshut-06
This draft is expired, but it is actually implemented by several vendors.

I implemented this.
http://www.slideshare.net/bduvivie/bgp-graceful-shutdown-ios-xr
I added an option to configure AS-path prepends in case the gshut community was not supported by peers.

Thanks,
Jakob.


> Date: Tue, 10 Jan 2017 03:51:04 +0100
> From: Baldur Norddahl <baldur.norddahl at gmail.com>
> 
> Hello
> 
> I find that the type of outage that affects our network the most is
> neither of the two options you describe. As is probably typical for
> smaller networks, we do not have redundant uplinks to all of our
> transits. If a transit link goes, for example because we had to reboot a
> router, traffic is supposed to reroute to the remaining transit links.
> Internally our network handles this fairly fast for egress traffic.
> 
> However the problem is the ingress traffic - it can be 5 to 15 minutes
> before everything has settled down. This is the time before everyone
> else on the internet has processed that they will have to switch to your
> alternate transit.
> 
> The only solution I know of is to have redundant links to all transits.
> Going forward I will make sure we have this because it is a huge
> disadvantage not being able to take a router out of service without
> causing downtime for all users. Not to mention that a router crash or
> link failure that should have taken seconds at most to reroute, but
> instead causes at least 5 minutes of unstable internet.
> 
> Regards,
> 
> Baldur



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