So, I have a gateway router, and 1 router in between my end point router and my first downstream BGP router. I have the 3rd router and the customer router with an active BGP session and I’m receiving their route just fine. My question is how I configure the router in between to pass the BGP path data from my customer out to my upstream BGP peer session, and the default routes from my gateway router to my customer router.
1st question obviously would be, do Have to enable BGP on the router in between as well? Or is there a way to pass the BGP data directly from my 3rd router to my gateway router where BGP is already live between my AS number and my upstream peers AS ?
This question isn’t specific to VyOS. It seems you need to brush up on your BGP knowledge.
I HIGHLY recommend checking out NSRC’s content on BGP. You can find it under BGP: How BGP Works | NSRC Training Resources.
Here are a couple of pointers:
- To advertise customer routes, you’ll need to share the customer prefixes with your upstream provider so they can update their routing policies and inform their upstreams accordingly (typically requires sending a Letter of Authorization).
- Yes, you can establish a BGP session between Router 1 and Router 3; BGP doesn’t require Layer 2 adjacency. However, depending on Router 2’s involvement in the BGP domain, consider implementing an iBGP full mesh between the three routers, which is the simplest solution but not scalable. Alternatively, you could designate the middle router as a route reflector or use an eBGP-driven design (an advanced topic).
- Use the ‘default-originate’ parameter on the customer-facing BGP sessions to send a default route. Just ensure you apply proper route filtering to avoid sending any other routes from your global table.
- Filter customer prefixes on customer facing BGP sessions. Make very sure you explicitely only allow the prefixes you want to advertise, nothing else.
In terms of routing policies, check out https://bgpfilterguide.nlnog.net/ for best-practice route filters.
Hope this helps!
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Okay, after watching that, that was all information I already know. But after playing around, I did get an active BGP IPv6 session established between my customers end point router and my main gateway router. The only issue I have no is that my end point customers AS is not being included in the path, so I need a config example to figure out how to get it to pass my customers AS number and them register as a downstream from us, and us register as an upstream for them.
