BGP route filtering

RouterOS Forwarding Protocols
1

We are switching to Microtik for our BGP router and we are currently using OpenBGPD. Mostly things are pretty straight forward when switching over but there are some differences I can’t seem to wrap my head around. For example, we have the following route filters on OpenBGPD:

match from group “group1” source-as AS 1234 set {localpref +150}
match from group “group1” transit-as AS 1234 set {localpref +50}

source-as being the rightmost AS number and transit-as being all but the rightmost AS number.

Is there any way to do this on RouterOS? I know you can do multiple rules per chain, but I can’t seem to figure out how this could be done.

2

There unfortunately isn’t a + or - operator, so you need to set local preference explicitly.


/router filter add bgp-as-path="^(111_)+(222_)+$" set-bgp-local-pref=150

as111 is transit and as222 origin


"_222$"

Originated by as222


"_111_"

Transits as111

3

You need to escape out $ via cli, eg:

bgp-as-path="^(111_)+(222_)+\$"