external Border Gateway Protocol. BGP is a routing protocol used to share reachability information thru independent routing domains; iBGP is when you use BGP to manage your own networks. eBGP is what is spoken between different AS (Autonomous Systems) across the core (routers without a default route) internet. You'll often read "Country X lost 50% of traffic for N hours due to eBGP issues".

In this context it was a typo (now corrected).