Internal Border Gateway Protocol (IBGP)

Definition - What does Internal Border Gateway Protocol (IBGP) mean?

The Internet Border Gateway Protocol (IBGP) is a robust and scalable Border Gateway Protocol (BGP) routing data between Internet Service Providers (ISP) in autonomous systems (AS). It does not use Interior Gateway Protocol (IGP) metrics to make routing decision, instead it uses network path, policies and rulesets for the routing decisions.

IBGP ASes connect computers in a full mesh configuration, which requires every router to maintain all network router sessions.

Techopedia explains Internal Border Gateway Protocol (IBGP)

IBGP configuration steps are as follows:

Binding interfaces to virtual routers
Binding interfaces to zones
Assigning IP addresses to interfaces

IBGP route reflectors and confederations help reduce processing overhead and enable AS interior gateway protocol (IGP) packet routing. Route reflectors are usually single routers but may be peer-configured.

Confederation ASes implement detailed network policies for large AS configurations, which encompass internal and smaller ASes. Confederations specify confederation identifiers. Confederations may be used with route reflectors. These route reflectors and confederations must continuously oscillate until IBGP design rules are established.