Mikrotik – View Large Routing Tables – BGP Full Feed
If you are connecting your Internet routers to your providers via BGP, you will quickly notice that it is difficult to view the route table…and when a normal feed is 510K+ routes, I’m sure you can imagine why. A single full feed consumes somewhere around 256MB of RAM…so don’t try this with an RB750! As Tom would say, “Get bigger rooters B*****s!”
At any rate, when you open winbox, go to ip route, you see this:
What you want to do is use some filtering. You will find this just above the list of routes…or lack there of:
Notice that I used the “is” condition. This means it will look for this EXACT route.
If we want to put in a subnet and find all routes that are contained within it we would switch to the “in” keyword:
Notice it found 275 routes.
We can accomplish the same via CLI…with even more functionality actually, but we will keep it simple.
Exact match:
1 | /ip route print where dst-address=0.0.0.0/0 |
Match subordinate routes:
1 | /ip route print where dst-address in 8.0.0.0/8 |
On the CLI we can add some additional keywords…like detail!
1 | /ip route print detail where dst-address=0.0.0.0/0 |
As you can see, adding the detail option gives us the BGP peer that we learned it from, their AS#, and gateway information. All extremely useful information.
Let me know about your route table tricks in the comments, and as always, happy routing!
Hello Greg,
Thanks for share your knowledge.
I has one question about BGP and Mikrotik.
Right now I’m needing to establish a BGP session with two differences ISP and I need to receive the Full Routing table from both ISP.
I read in that Mikrotik Routers(Including CCR) only use one CPU Core for BGP processing… The question is Can I use a Mikrotik Router for this scenario? If the answer is yes, can you suggest a specific Mikrotik Router?
If your answer is “no”, which router can you recommend for me?
Thanks beforehand.
@Jesus
The CCRs are doing OK right now. If you have an x86 with larger procs, that is a great option also.
From what I understand ROSv7 is supposed to multithread the BGP process, and we will probably hear about that very soon.