Hello Remi, Thanks for that, I saw a presentation from Paulo Lucende about this. for us as an eyeball ISP, my request is slightly simpler, because I can Advertise my routes to all peers / transit so my downloads will happen, to sort the upload I need to learn and install the routes. (content providers need to use netflow to learn which prefixes should be installed on the switch to deliver content to the users)
I like the NFsen idea, however I think for a simple eyeball ISP we could be able to achieve it by adding a default + exceptions summarisation to openBGPd ( I would rather not create more dependencies on our BGP ) I want to install the minimum number of routes for transit so that I am confident the packet will reach the intended destination and then leave the rest of the switch CAM for Prefixes learned on a local internet exchange. Thanks for the feedback on the Spotify Use case... On Sat, 22 Sep 2018 at 09:11, Remi Locherer <remi.loche...@relo.ch> wrote: > > On Sat, Sep 22, 2018 at 08:22:52AM +0100, Tom Smyth wrote: > > OpenBGPd Feature Request / Question if the Feature Request > > is something the community would use ? > > > > Background, > > Ideally we would run full tables so that we have visibility > > on reachibility of a prefix via a transit provider, > > > > Problem: routers that support this functionality Reliably > > are quite expensive, (or inexpensive and unreliable) > > Workaround: > > so many people accept default over BGP from transit and > > then peer locally on the exchange > > Issue with this is that you lose visibility of wheather > > an ip is actually reachable via your transit provider > > > > > > Question: > > is it feasible to have a hybrid between a default route > > for transit and bgp full views of transit? > > Is it feasible to: > > a) take two or more full bgp feeds from transit, > > b) diff them continuously on a software route server, > > c) install a default route to your preferred transit provider > > on your lower cost L3 Switches / Routers > > d) install differences in prefix reachibilitity to the > > appropiate transit provider (which would otherwise not > > be reachable via your preferred transit provider) > > > > > > Why am I asking this ? > > I want to have the advantages of full views of internet > > but I want the simplicity of a single default route + > > any exceptions. and use more cost effective hardware > > > > Im asking this in the context of an ISP which is not > > proividing transit to other ISPs > > > > I ideally would like to run multihop BGP to my transit > > providers, > > and then use a L3 switch for forwarding in hardware > > (something like an arista / Broadcom Trident II ) > > which can take up to around 128k routes on its asics > > > > If it is feasible to do what is involved in adding it > > to OpenBGPd and is this something the wider community > > would use / enjoy ? > > > > Your feedback would be really appreciated... > > Yes, it is feasible. Spotify is doing something like this. > https://blog.ipspace.net/2015/01/sdn-router-spotify-on-software-gone-wild.html > > In short: analyse where 80% of your traffic goes to (nfsen) and write a > filter to only install those prefixes in addition to the default route. > > A year ago I did this analysis for the network I operate: > 80% of our Internet traffic went to 20 ASs and was covered by ~9k prefixes. > > Cheers, > Remi
