Unlike a majority of the routing protocols BGP is designed to work between ASNs (Autonomous System Number), you get two different types of BGP, most of the time we will be working with eBGP(Exterior Border Gateway Protocol), however some configurations can make use of iBGP (Interior Gateway Protocol) where BGP connects within the same ASN. We tend to avoid the latter as we tend to use routing protocols like OSPF or IS-IS to handle interior routing.
What makes BGP a great routing protocol is all the attributes that you can also specify between the peers. Giving you control to potentially set how traffic flows and allowing for easy installation for things such as failover.
Without going into all the detail BGP takes two to tango, you will primarily be forming a neighborship with a remote router most of the time on the same broadcast domain. Configuring BGP on MikroTik is very straightforward and you will mainly be working in 3 sections.
1) The BGP instance, this is where you configure your ASN details
2) The BGP peer, this is where you configure your neighbor’s ASN details
3) The Networks, here you will be defining which networks BGP is advertising (Note you can redistribute routes through the instance section as well)
Now that we have briefly discussed what BGP is we will look at how to configure this between two routers.