nanog mailing list archives

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


From: "Jakob Heitz (jheitz)" <jheitz () cisco com>
Date: Tue, 10 Jan 2017 19:51:57 +0000

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 () 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


Current thread: