CoreBGP – Plugging in to BGP

I love this.

I tried using GoBGP to write a simple golang-based alternative to ExaBGP (which is great and missing from this article) and was discouraged because GoBGP simply did too much, which I didn't need (routing tables) and making it not do those things was extremely time-consuming, so much so that I started writing my own BGP implementation in Go, but, pretty quickly realized it was a larger project than I wanted to take on at that moment, so it got shelved. Exabgp was "good enough".

It's fun implementing a BGP speaker from scratch. I implemented one about 15 years ago in Java which was designed much like this library. It was proprietary code which we used to advertise programmatically-determined routes to our edge routers. Connecting to a router, walking through the state machine changes, and debugging unexpected behavior (from both misunderstanding the RFC and from finding bugs in vendor implementations) was a great learning experience.

Interesting, reminds me a tiny bit of the BGP listener in Java that was written back at Smallworks https://github.com/pjz/java-bgp

I'm using rpc calls to GoBGP to get routes for my evpn project. Using CoreBGP as a library and talk directly to other peers might be a better idea.

Quite interesting, both the project and the ideas behind it and in the referenced paper. I really need to dust off that BGP lab setup...