Show BGP advertised routes on MikroTik RouterOS 7 (the old way)

Every network vendor has its own philosophy and CLI. With MikroTik I have a love-hate relationship: I love how versatile and good value their devices are, and dislike how often the product feels unfinished.

Coming from Cisco or Juniper, you expect a simple command to show the routes you advertise to a BGP neighbour. In RouterOS 7, it felt more like sending a rocket to the moon.

The MikroTik way

In Cisco IOS or Juniper Junos, commands tend to be straightforward. RouterOS has its own dialect. On Cisco, show ip bgp neighbor x.x.x.x advertised-routes does the job, and there would be no blog post. On RouterOS you have to work around it. I am quite sure this is a work in progress, and at some point they will introduce a more friendly command for that.

The workaround

1. List the BGP connections and note the ID of the peer you want to look at:

   [admin@mikrotik] /routing/bgp/connection> print

2. Make the router keep the attributes it sends to that peer (ID 0 here):

   [admin@mikrotik] /routing/bgp/connection> set 0 output.keep-sent-attributes=yes

3. Save the advertisements of the session to a file with a unique name:

   [admin@mikrotik] /routing/bgp/session> dump-saved-advertisements 0 save-to=peer.pcap

4. Read the file:

   [admin@mikrotik] /routing/stats/pcap/print detail where file=peer.pcap

The announced prefixes are listed in the .nlri= fields.

A work in progress

Compared with Cisco IOS or Juniper Junos, this is far from simple, which to me suggests a feature that was still being built. It may cause a facepalm, but it works.