A Day in the Life: The Global BGP Table
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A Day in the Life: The Global BGP Table
1–10 of 29 posts
Re: A Day in the Life: The Global BGP Table
#2I learnt quite a few things I didn’t know about BGP from this article, probably most interesting how chaotic it is!
I’d definitely be interested to read some follow-ups, diving into more details.
Re: A Day in the Life: The Global BGP Table
#3If anyone wants to learn about BGP (especially day-to-day stuff for peering scenarios), the Network Startup Resource Center out of U.Oregon has a good series of videos going through things:
Re: A Day in the Life: The Global BGP Table
#4Nice article.
That flapping from EpicUp 140.99.244.0/23 prefix should have been subject to route dampening. This is per peer or per prefix rate limiting typically enforced on all peers by ISPs to prevent this exact issue of a single prefix making up a significant portion of the global BGP churn.
I’m unconvinced of the correlation between the updates that the author attributed to knock on effects. It would be pretty janky to have your advertisements be based on the path to other autonomous systems’ prefixes, especially unstable ones.
I don’t think there is a 40 minute periodicity either (at least there wasn’t 8 years ago when I was deep in the BGP world). Smells like what this dataset happened to show either by luck or because of the network the author was getting the BGP feed from.
If you dig into the data and look at which AS’s and prefixes are experiencing changes, you’ll find it’s all over the place and there isn’t really any bigger pattern.
On any given day there are usually a few noisy ISPs because of bad circuits or misconfigurations. Then there are new prefixes flapping in and out as a new thing is brought online for the first time, etc. Then sprinkle in path changes for regular draining maintenance, etc.
It’s simultaneously both fascinating and a little horrifying how a little ISP in Kansas experiencing a fiber consuming backhoe shows up on routers in Perth. Yet the frequency of updates is kept to <10hz globally through tons of hand tuned policies.
Re: A Day in the Life: The Global BGP Table
#5/me thinks to himself : real nice font on that page
Re: A Day in the Life: The Global BGP Table
#6What is the easiest way for average joe to get hands on BGP data? If I wanted to try do similar analysis and don't happen to have a friend at ISP.
Re: A Day in the Life: The Global BGP Table
#725 years ago, I worked for a small ISP (back when there was such a thing.) When I started there, we had one upstream ISP. I was charged with getting us multihomed. I found some tutorials written by Avi Freedman (1). I don't know what I would have done without him. He made an intimidating topic approachable. Thanks to him, I got us a /20 from ARIN and advertised our routes to two different peers. It was fascinating to learn how it all worked. And the more I learned about it, the more amazed I was that it worked at all.
Avi
Re: A Day in the Life: The Global BGP Table
#8What is the easiest way for average joe to get hands on BGP data? If I wanted to try do similar analysis and don't happen to have a friend at ISP.
Re: A Day in the Life: The Global BGP Table
#925 years ago, I worked for a small ISP (back when there was such a thing.) When I started there, we had one upstream ISP. I was charged with getting us multihomed. I found some tutorials written by Avi Freedman (1). I don't know what I would have done without him. He made an intimidating topic approachable. Thanks to him, I got us a /20 from ARIN and advertised our routes to two different peers. It was fascinating to…
I used to work for Avi at Kentik. He is a smart, nice person and remembered writing these articles fondly to help people out!
Re: A Day in the Life: The Global BGP Table
#10Nice article. That flapping from EpicUp 140.99.244.0/23 prefix should have been subject to route dampening. This is per peer or per prefix rate limiting typically enforced on all peers by ISPs to prevent this exact issue of a single prefix making up a significant portion of the global BGP churn. I’m unconvinced of the correlation between the updates that the author attributed to knock on effects. It would be pretty j…
Route dampening has mostly fallen out of fashion with networks these days.
Most setups were horribly misconfigured and (most) routers are no longer extremely CPU starved as they once were, That doesn't mean that it does not still exist of course, when I did bgp battleships ( https://blog.benjojo.co.uk/post/bgp-battleships ) I found that 3356 (at the time) was doing route dampening, so play had to be paused for a while.