OSPF between firewall ando two PPPoE Server

RouterOS Forwarding Protocols
1

Good afternoon I need OSPF between firewall ando two PPPoE Server

…Firewall
…/…
…/…
…/…
…PPPoE Server1…PPPoE Server2

I can not find documentation, I have to do in one area?

2

Definitely just use area 0 for such a simple topology. Mikrotik calls area 0 “backbone” so use that area.
Multi-area OSPF is for a much larger network than you’re using.

Since you gave no IP addressing in your example, I’m going to use 10.0.0.0/24 as the IP network between the firewall and pppoe servers. Replace that with whatever is really configured for your network.

So let’s say ether2 is the interface towards your PPPoE servers- and it’s 10.0.0.1/24

/routing ospf
instance set default router-id=10.0.0.1 distribute-default=always-as-type-1
network add network=10.0.0.0/24 area=backbone

For the pppoe servers, I would suggest:

/routing ospf
instance set default router-id=10.0.0.x redistribute-static=as-type-2
interface add network-type=broadcast passive=yes
interface add interface=ether1 network-type-broadcast passive=no
network add network=0.0.0.0/0 area=backbone

(assuming that ether1 is the interface leading to the firewall)

This will originate all locally-connected IP addresses/networks as native interior-to-ospf routes, and redistribute the static routes into OSPF as external routes - be sure not to have any static routes configured which will point to the firewall or another pppoe server, or else you could end up with routing loops.

This is a very basic configuration and there are some deeper, more-involved best-practice things I’ve left out, but this should be enough to get you going.

If you want to try a little more for best practice, don’t use 0.0.0.0/0 on the pppoe server as the only network - instead, use the actual IP ranges that are connected to the server, and make an ospf-out filter which allows routes with a certain route tag (e.g. 101) and then put this tag on static routes that you want to be injected into OSPF, but leave the tag off of “private” static routes that you don’t want leaking into OSPF - for instance, make a tagged “supernet” of the IP range that each pppoe server has, but don’t tag any subnet of it - this will keep the routing table lean and mean.