[c-nsp] Default Route recalculated every 60 seconds.

[Bradley Ordner]

Just thought I would update this thread, the carrier ended up labbing this for us and found it did not occur in the lab. The only difference was the IOS on the CE router and only receiving a default, not a partial table and default.

I still couldn't believe it, so we updated our router to 16.09.05 and the default is stable.

We were originally on asr1001x-universalk9.16.06.04.SPA.bin.

I will take a packet capture (on the router) again and check if the default update is coming every sixty seconds.

Brad


________________________________
From: Gert Doering
Sent: Tuesday, April 21, 2020 7:10 AM
To: Bradley Ordner
Cc: Gert Doering; James Bensley; cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Default Route recalculated every 60 seconds.

Hi,

On Mon, Apr 20, 2020 at 08:54:27PM +0000, Bradley Ordner wrote:
> Thanks Gert, I will now ask them to do packet capture on their side and see if they are advertising this default to any other customer every 60 seconds.
>
> Something else I noticed, we only accept routes less than or equal to /18. I noticed that many updates come in, for different prefixes. I can???t see how the Internet could be that unstable unless there is something wrong with their network. Wonder what is the norm when seeing so many prefixes change.

The Internet is huge - 70.000 networks(!) connected together.  Things
are rebuilt and changed all over the place all the time, and links and
devices fail and get repaired all over the time.

So yes, there's a constant stream of BGP updates.

Google for Geoff Huston.  He's done a number of very good presentation
on the dynamics of BGP updates over time.

gert
--
"If was one thing all people took for granted, was conviction that if you
 feed honest figures into a computer, honest figures come out. Never doubted
 it myself till I met a computer with a sense of humor."
                             Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany                             gert at greenie.muc.de