OSPF and PPPoE Setup
From MikroTik Wiki
This is from http://forum.mikrotik.com/viewtopic.php?f=2&t=24797
Once we have the IP Addresses, Gateway, and Routing information from our service provider, we can begin by creating and configuring the OSPF area, followed by setting up the PPPoE server. In this example 10.0.108.18/28 is the routing network given to us by the provider, with the gateway 10.0.108.17. The public IP Address block we have been given is 10.0.110.0/24. Once these steps have been completed, the PPPoE username and passwords that are set up will be on the internet with an IP Address out of the 10.0.110.2-10.0.110.254 range. Our public facing network card is ether1.
IP Address Configuration
This gets your MikroTik Router out on the internet with an accessible public IP address.
/ip address add address=10.0.108.18/28 interface=ether1
This enables OSPF for the 10.0.110.0/24 network.
/routing ospf area add area-id=0.0.0.110 name=public_110 /routing ospf network add area=public_110 network=10.0.110.0/24 /routing ospf area range add area=public_110 range 10.0.110.0/24 cost=default advertise=yes
First, create the public IP Address pool.
/ip pool add name=public_pool ranges=10.0.110.2-10.0.110.254 next-pool=none
Next we create a PPP profile, add a user, and then start the server on interface "ether2".
/ppp profile add name="public_profile" local-address=10.0.110.1 remote-address=public_pool /ppp secret add name=user password=changeme service=pppoe profile=public_profile /interface pppoe-server server add service-name=public_internet interface=ether2 default-profile=public_profile \ \... one-session-per-host=yes authentication=pap max-mtu=1480 max-mru=1480
Now, this MikroTik Router should be routing all PPPoE clients on your network out on to the internet with their own public IP addresses.