Ios

A while back I posted about routing filter generation via bgpq3 for Cisco (ios and XR) and Juniper JunOS based routers. I have received a number of emails in last few months about automated filter generation for Mikrotik routeros. Since Mikrotik’s CCRs are getting quite popular across small to mid-sized ISPs. So this blog post is about ways for generating filter config for a given ASN via IRR. One can use such logic with some kind of remote login mechanism like rancid (look for mtlogin here). I tried building around bgpq3 but it seems more easy with another popular tool in the domain called IRR Power Tools. Once IRR Power Tools (IRRPT) is setup, it allows us to fetch prefixes based via Internet Routing Registries and also aggregates them.   So, for instance, let’s pick AS54456: