BGP Implemented in Go

https://github.com/osrg/gobgp

by eatonphil • 4 years ago

136 61 4 years ago

github.com

rayhaanj• 4 years ago

I've been working on a BGP implementation in Rust over the last few years: https://github.com/net-control-plane/bgp/

It's still in a proof of concept stage and nowhere as complete as GoBGP though.

ternaryoperator• 4 years ago

Thank you for having a front page that actually says what BGP is.

zinekeller2• 4 years ago

I'm not sure if this will help explain the culture or not, but this is from the NTT (the Japanese telecommunications company), so probably they thought that everyone knew what BGP is (since that you probably won't encounter this otherwise).

Also, they have a Rust version: https://github.com/osrg/rustybgp

0x20cowboy3• 4 years ago

I may have missed it, but I read the read me, looked at the main site, looked at the beginning of getting started… nowhere says what BGP stands for / is.

I get it’s written in go, but I have no idea what BGP is. Big green pages, binary grepping pipes, boisterous gambling pachyderms?

Jokes aside, y’all might want to give a brief about what this is for us uninitiated.

fragmede• 4 years ago

In this context, BGP stands for Border Gateway Protocol.

I opened a PR to fix that. https://github.com/osrg/gobgp/pull/2535

charlieyu1• 4 years ago

I am finding for a long time that what BGP is… The docs even linked Golang without linking BGP. I thought it was something about board games

ZiiS• 4 years ago

Border Gateway Protocol how the internet shares its routing table.

zinekeller2• 4 years ago

Border Gateway Protocol (https://en.wikipedia.org/wiki/Border_Gateway_Protocol), basically the GPS of the internet (not technically the same, but it's close enough).

Cloudflare has already a good explanation on how it works, so I'll just point everyone out to this article: https://www.cloudflare.com/learning/security/glossary/what-i...

Also, about that undefined BGP. I'm not sure if this will help explain why BGP wasn't explained, but this is from NTT OSRG (Open-source Research Group), so probably they thought that everyone knew what BGP is (since that you probably won't encounter this otherwise).

Also, they have a Rust version: https://github.com/osrg/rustybgp

cortesoft3• 4 years ago

BGP is pretty foundational to the internet. At some point, you have to assume hour audience knows the basics. Not everything is an intro.

Also, if you don’t know what BGP is, you aren’t going to be interested in a project implementing BGP.

teeray• 4 years ago

It’s still wise to define acronyms before you use them to enable future Googling (links are better!). Three extra words is a small price to pay to make documentation more friendly to newcomers.

0x20cowboy3• 4 years ago

I’ve been on the internet for quite a long time, but I’ve never heard of it before. So maybe it’s basic knowledge for a given discipline, but maybe not for others?

It’s also, I assume by the authors, submitted to hackernews which is a pretty diverse place. “Basics” is relative.

I am not saying there should be a dissertation about how the thing works, but it’s generally bad form to use abbreviations without using the long form at least once - for people who would indeed like to search for more information.

natefinch2• 4 years ago

How can someone know if they're interested or not in an implementation of BGP if they don't know what it is?

I have been a professional software developer for 22 years with a 4 year CS degree from a good school, and I only ever heard of BGP for the first time last year. Most developers never need to know about BGP. People learn new stuff every day.

The point stands. Define your acronyms unless they're really really basic, like HTTP or JSON.

nmz• 4 years ago

It's that thing facebook messed up the other day and nobody could connect to it.

betterunix2• 4 years ago

BGP is the de facto routing protocol of the Internet. The basic problem that it solves is computing and distributing routes between independently operated networks. It is actually a pretty ramshackle protocol (among other things it usually uses TCP, which can create some interesting problems [1]) but it is the only widely deployed protocol that can handle the scale of the Internet.

In theory BGP can be used within a single network, though it is not well-suited to such an application except in very large networks. Facebook is known to use BGP internally [2]. Usually an "interior gateway protocol" like OSPF or IS-IS is better for internal routes, with BGP then distributing those routes to the external networks from the gateway routers (i.e. those routers that interconnect the networks). BGP can also be used for other, more niche applications within a single network, like setting up VPNs (VPLS, VPNv4, etc.).

[1] https://blog.benjojo.co.uk/post/bgp-stuck-routes-tcp-zero-wi...

[2] https://research.facebook.com/publications/running-bgp-in-da...

freedomben• 4 years ago

Maybe a dumb question nowadays because I stopped using Go around the 1.6 days, but is there still a stop-the-world garbage collector, or any other potential blockers for high performance/real time?

A previous company I worked with chose to build in C++ instead of Go because of that, as the performance requirements were very, very high. I would imagine a serious BGP usage would have very high requirements?

mitchs• 4 years ago

It depends on the context. Not every bgp speaker needs the full internet table and frequent route changes. If you use the network to balance traffic across servers, you just need a bgp speaker on a server to inject a few routes for the ip addresses it will handle. In that case a good api outweighs performance.

woah• 4 years ago

BGP doesn't have very high performance requirements. It does not handle any internet traffic. All it does is configure the kernel routing tables. Even if there's some crazy 1 second GC pause it will not greatly affect the performance of the router.

lima2• 4 years ago

Sending or receiving an internet full table (and potentially applying filters/aggregations) is still quite performance intensive, since it needs to happen quickly.

A one-second GC pause won't hurt you but managing the necessary data structures in memory can be challenging.

Anecdotally, gobgp is quite a bit slower than hand-optimized C implementations like frr (not that it matters for most gobgp use cases).

remram• 4 years ago

I don't think BGP requires real-time. Increasing throughput via multithreading is probably much more impactful (for large deployments) and otherwise it doesn't matter.

tptacek4• 4 years ago

A BGP route server might be the platonic ideal of a Go problem: it's demanding enough not to be tenable in Python, but not real-time or kernel resident, and mostly data structure --- and just a couple data structures --- intensive.

justinsaccount3• 4 years ago

not to be tenable in Python

https://github.com/Exa-Networks/exabgp is written in python

natefinch2• 4 years ago

Go's garbage collector has super short stop the world now, about 1ns IIRC. Most of the work is done concurrently from the main process threads.

d110af5ccf• 4 years ago

1ns

Microsecond, perhaps. Likely millisecond. Nanosecond is faster than a single CPU instruction.

kxrm• 4 years ago

This is great, I have been learning "bird" and finding information on the web about using bird is very challenging since adding bird to any search doesn't necessary make the results better. If this project can maintain and keep their documentation clear, I would totally consider switching to this instead.

alaties• 4 years ago

Yeah... Bird configurations are a little rough to learn. The examples they have on the website are pretty lacking. Their mailing list is usually helpful though.

Quagga is usually easier to find examples for since it's modeled after Cisco switch syntax for configuration (same basic syntax of arista switches).

Both of these really suck to learn as a programmer since you're usually coming into these without much of a network engineering background. I remember struggling a lot with both of these config syntaxes until a network engineer took me under his wing and taught me basics, principles, the engineering challenges of packet switching at scale, etc.

kisamoto• 4 years ago

As a BGP alternative (in Go) has anyone checked out SCION?

https://github.com/scionproto/scion

wmf• 4 years ago

I gave up when I saw new packet headers which means you might not be able to use existing ASICs.

xyquadrat2• 4 years ago

SCION looks very promising, and by now it has also been deployed in Switzerland's financial network, so it seems ready for production:

https://www.six-group.com/en/newsroom/media-releases/2021/20...

(Actually, the original creator of SCION teaches my CompNet course, which is pretty cool. His rants on BGP are quite legendary.)

bogomipz2• 4 years ago

"His rants on BGP are quite legendary"

I'm assuming the context of these is lectures? Are they online anywhere? If not could you share what specifically about the protocol they feel so strongly about?

kloch2• 4 years ago

Reading through the documentation it looks like this emulates the legacy IOS model of announcing all BGP routes to neighbors by default unless there is a policy configured.

This outdated model has caused countless route leaks over the years. Any new or updated BGP implementations should require an explicit allow policy for any route advertisement to take place (at least to eBGP neighbors). IOS-XR and JunOS require explicit policies.

This is covered in RFC8212: https://datatracker.ietf.org/doc/html/rfc8212

BGP Implemented in Go

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