Our connection to the Internet is via BGP through our ISP connected to a Cisco router. The Cisco is talking to a 2.9.26 Mikrotik via OSPF which is talking to another 2.9.26 Mikrotik. The final Mikrotik connects via BGP to a customer Cisco router. So, we have:
ISP->Cisco 1->Mikrotik 1->Mikrotik 2->Cisco 2
If I don’t want to run BGP on Mikrotik 1 but want my customer to connect via BGP to Mikrotik 2 is this possible just using OSPF inbetween? Or do I need to run multihop BGP between Cisco 1 and Mikrotik 2?
It depends on how many prefixex you want to announce to your customer. I strongly suggest NOT redistributing whole BGP (140.000 prefixes) to OSPF. Multihop BGP is much better idea.