Well its rather complex to give an example.
Im sorry the topic deviated from the intended subject, but the initial scope was pretty much blown away since i cannot do IGP load balancing
Shortly, im trying to change all my current equipment with Mikrotik enabled devices (rb1000s, PCs, etc).
The situation is like this:
- 3 full bgp table upstream providers (about 870000 rib entries, ~290000 prefixes in the routing table)
- 3 peering tables (~24000 prefixes)
- all of the above would be connected to 2 RB1000s, one as a primary, the secondary running as a backup system, each having sessions to each upstream and peering providers
- some 30 distribution routers, running BGP with the above RB1000s which acts as route reflectors
- some 20 clients that runs BGP with us, some obtaining the global bgp table+peering tables, some just peering tables and some just the default.
The way it is right now, each table coming from either provider, is marked with a different community. Each downstream distribution router has its own internal announcements, its own subnet origination in the internet and some of them have bgp running with customers. Each internal announcement is marked with communities that wont let those announcements leak to the upstreams, also each router has its own ID that is used to mark the subnets, so we know where the route comes from real quick.
Each customer that originates a subnet, receives the same router id marking (appended), also the customer has a choice of communities to manipulate announcements to us or to the upstream provider (such as setting local pref, weight, prepending, etc).
Having a strong cisco background (quagga also), i find it pretty difficult to deploy complex filtering rules with Mikrotik, even when the most simple rule i added doesnt do its job properly and apparenlty there's no way to debug BGP in Mikrotik. I would pretty much like to see something like "test chain" in filtering rules so one would know whether to expect something or not.
Remember this is the view of a noob in Mikrotik. Apart from the filtering rules, i absolutely love it