Adding / Appeding bgp community to static or connected route

RouterOS Forwarding Protocols
1

Hello,

Any suggestions on how to accomplish this if it is possible ? (translating from Cisco world).

ip prefix-list our-cidr permit 68.142.0.0/19 le 24

route-map static-bgp permit 10
match ip address prefix-list our-cidr
set origin igp
set community 11280:115

I know I can use the instance filter to append the community 11280:115 when sending the route to the peer.

The above in cisco world will actually add the bgp community to the local static routes as well, so that one was to query the local routing table for all routes included in the community 115 the local routes will also show up.

Many thanks in advance..

Faisal

2

You could set a comment on the static route. Connected routes are dynamic and can’t have any of their properties edited.

3

Well the idea behind the cisco config is that with the Static Routes also able to to have the bgp community attribute tagged to them, then one can do a simple one step filter for sending routes to another peer.

if this is not possible then it would be have to be a multiple lines to do the equivalent ..
i.e. one set of filters to send internal connected /static routes
and another set of filters to send other bgp learned routes which were tagged with community upon being received..


Thanks

4 
/routing filter
add chain=bgp-static-out action=accept prefix=68.142.0.0/19 prefix-length=19-24
add chain=bgp-local-out protocol=static match-chain=bgp-static-out set-bgp-communities=11280:115
add chain=bgp-out locally-originated-bgp=yes invert-match=no action=jump jump-target=bgp-local-out
add chain=bgp-out action=accept bgp-communities=11280:115
add chain=bgp-out action=discard

/routing bgp peer set some-peer out-filter=bgp-out

That should do what you want. I’ll explain. The routing filter process goes like this:

  1. Start in ‘bgp-out.’ If the routes are originated from ‘self’ then jump to chain ‘bgp-local-out’
  2. If a locally originated route is actually redistributed from static, and is present in the ‘bgp-static-out’ chain then set the BGP community 11280:115.
    (bgp-local-out ends. We jump back to bgp-out)
  3. Permit routes with community 11280:115.
  4. Discard the rest.

Creating a separate bgp-static-out chain lets you utilize that chain like a prefix-list. You can have one rule in ‘bgp-local-out’ which then matches any routes contained in the chain / ‘prefix-list’ bgp-local-out.

I haven’t tested this but it should work. Hope this helps.

5

awesome… Thanks this helps me a great amount to understand how the filters work as well.

is there a good resource that you would recommend reading so as to be able to get a better understanding on all the different CLI options possible when writing the filters ?


Many Thanks :slight_smile:

6

http://wiki.mikrotik.com/wiki/Manual:Routing/Routing_filters

And some hands-on work / testing. :slight_smile: