Community discussions

MikroTik App
 
joegoldman
Forum Veteran
Forum Veteran
Topic Author
Posts: 766
Joined: Mon May 27, 2013 2:05 am

OSPF force gateway from BGP

Thu Mar 11, 2021 1:35 am

Hi Forum,

Not sure I worded the title right - but looking for a solution to my issue.

Consider a WISP network map of various towers linked together (not a 'FULL MESH' but rather random PtP links to create some triangles / loops etc)

We run OSPF between all these sites - and it runs quite well - and all our data comes back to our gateway at our main DC where we BGP to the world.

The problem I am having is - I have a customer on R10 (so a way down the line through a few sites) that now wants to advertise BGP out to the world. I have set them up with multi-hop BGP to R1 which is established, and the route gets installed into the route table with the nexthop the actual BGP router, but resolving to the next tower - problem is OSPF now thinks R1 holds the route (which is true) and loops it back to itself.
From R1, to be redistributed out to the rest of the OSPF peers - how do I tell them to go to R10, without creating some kind of static route on R10? Is there a way to tag the route, so it will be redistributed across all OSPF neighbours to look for R10?

I am trying to avoid tunnels, static routes, or bringing CPE into OSPF, along with avoiding special rules to push out to every tower router - so BGP controls all (As the customer will be dual-homed, and in the instance our link to them goes down we want to withdraw the route so our own customers route via general internet to their second provider)

Hope this makes sense - and happy to learn of some possible solutions.
 
mducharme
Trainer
Trainer
Posts: 1777
Joined: Tue Jul 19, 2016 6:45 pm
Location: Vancouver, BC, Canada

Re: OSPF force gateway from BGP

Thu Mar 11, 2021 2:36 am

Hope this makes sense - and happy to learn of some possible solutions.
This might be a solution for you:

https://www.computerweekly.com/tip/Scal ... n-the-edge

The article is old but the information is still correct.
 
joegoldman
Forum Veteran
Forum Veteran
Topic Author
Posts: 766
Joined: Mon May 27, 2013 2:05 am

Re: OSPF force gateway from BGP

Thu Mar 11, 2021 3:04 am

Hope this makes sense - and happy to learn of some possible solutions.
This might be a solution for you:

https://www.computerweekly.com/tip/Scal ... n-the-edge

The article is old but the information is still correct.
Thats a pretty big network wide change -we have plans to move to something similar in future but was mostly hoping for a short term solution to my current problem - the real short term solution is im going to tunnel through the network and create a 1-hop adjacency so the hops inbetween don't have to worry about it, but its not ideal.

Who is online

Users browsing this forum: saktie and 16 guests