eBGP and iBGP are both flavors of BGP protocol. Let’s understand a short on what both terms means before comparing the functionalities of both –
External Border Gateway Protocol (eBGP) is a flavor of Border Gateway Protocol (BGP) used for communication between different autonomous systems (AS). eBGP functions as the protocol responsible for interconnection of networks from different organizations or Internet. eBGP is used and implemented at the edge or border router that provides interconnectivity for two or more autonomous system
Internal BGP (Border Gateway Protocol), iBGP is the protocol used between the routers in the same autonomous system (AS). iBGP is used to provide information to your internal routers. iBGP requires all the devices in same AS to form full mesh neighborship or either of Route reflectors and Confederation for prefix learning.
Now that we have brief of both the eBGP and iBGP protocols, below table compares them on various parameters –