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Comment by altilunium | Hacker News Reader

I think you need to manage a real (and large) network that's connected to global internet traffic in order to "play" with BGP. Well, you can tinker with it at home, but only by using a network simulator.

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It doesn't have to be that large. Many people have "personal" ASNs.

Check out this blog (not me, I just remember it from years back): https://blog.thelifeofkenneth.com/2017/11/creating-autonomou...

Really interesting post! Thanks for sharing

The author spoke about this story on my favourite podcast, On The Metal (of Oxide Computer Company)

https://onthemetal.transistor.fm/episodes/kenneth-finnegan

I worked an internship where I spent the summer setting up new equipment for a large corp that was replacing everything that AT&T had installed and managed with their own stuff. Nearly every office had their own ASN, everyone else got regular broadband or just a box of aircards depending on the number of users. I knew nothing about networks other than setting up my own consumer router at home so it was a pretty fun learning experience. I always got a smile on my face when I finally got vRouter to peer with our dummy AS in the office then we'd pack it all up and bring it out for installation over the weekend. I got offered a job to come back after I graduated but turned it down for something that paid better and was a lot more interesting. Honestly, I probably would be making more money as a network engineer now if I stuck with it.

The world is kinda screaming for experienced networking engineers ye

You can set up local BGP routers and peer them and play with it.

Another fun thing is to log into publicly available looking glass servers. Most ISPs (including very, very, very large ones) operate routers that have their full view of the BGP routing tables. They either run web interfaces that let you query those tables (more common) or make public ssh or telnet credentials to log in with roles that have very limited access to the available commands, but have read rights to those tables.

Internet researchers commonly use RIPE and RouteViews.

https://www.routeviews.org/routeviews/about/ https://stat.ripe.net/docs/02.data-api/

I've used BGP internally at my company for a decade, using AS65xxx range. At home I use BGP between the house, garage and shed, I much prefer it to OSPF.

Should we know what OSPF is too?

Unless you're heavily into networking and the ISP space, there's basically no need for you to know about routing protocols.

Depends if you do any routing on multipath networks. Most people don't so there's that.

ECMP? Can do that with static routes. As long as you have more than 1 router you could set up a routing protocol.

Or did you mean multipoint?

Open Shortest Path First (OSPF) is an "internal" routing protocol. Basically, it is a protocol for routers to share routes when all routers are managed by the same organization.

Border Gateway Protocol (BGP) has the primary purpose of sharing routes between routers managed by different organizations. It can be used within an organization too. It has a lot more control over how and which routes it sends and receives.

Depends how much you want to know about how networks work. Never ceases to amaze me how ignorant modern software developers are of the underlying technology, I guess that's because I'm from the pre-2010s when "Information Technology" was a general field.

I took some comp-sci and majored in "IT" in the 2000s. Lower level CS did not go over routing protocols, and the IT side never got into compilation, linking, state machines, or pointers.

Missed pointers!? Surprised me. (Am old)

In the 2000 my team had to deal with everything from compilation problems to hardware answering arp answers with fake mac addresses. The team consisted of a wide range of skills and abilities and information obviously leaks. While the DBA didn't need to know anything about OSPF, just by being in the same team as the network person they pick up how things work.

Now it seems that teams seem to be far more specialised and there's less cross-specialist learning.

> Never ceases to amaze me how ignorant modern software developers are of the underlying technology, I guess that's because I'm from the pre-2010s

Don't let my ignorance color your opinion of the youth of today.

I have trained people on network technologies, including the younger generation. It never ceases to amaze me how much they can get done without a clue about the underlying technologies. Sometimes it feels like they have some super power, because I can't operate without that knowledge.

CCNA had OSPF and that was part of my college curriculum in 2012.

It depends on what you study.

I did more of a sysadmin track, you (probably?) did pure comp sci/dev and would not encounter OSPF in a dev job (probably).

Same! At previous company I worked at we used BGP for all internal/external routing about 15 years ago despite all the poo-pooing by using BGP as an IGP. It was nice having no route redistribution and one command to monitor sessions.

BGP is chill and robust, OSPF is correct and fast. Both have their own place in a network.

You don’t need a large network to participate to BGP. You just need a /24 (IPv4) or /48 (IPv6) allocation, AS number, and a business class Internet connection that can do BGP. Might be out of reach for most hobbyists but not impossible.

You don't even need a business class connection. You can do BGP over a tunnel to a VPS or colo.

On top of the already suggested local BGP routers you can also use https://dn42.us/ to test a bit more real-world like scenarios.

Not really, you can learn it just fine with simulators and a few routers. Designing and operating BGP in a large network is another thing though.

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