What describes Full Mesh IBGP?

Full Mesh IBGP refers to a configuration where every router within an Autonomous System (AS) establishes a direct BGP connection to every other router in the same AS. This setup ensures that all the routers can exchange routing information with each other, which is critical for maintaining consistent and loop-free routes within the AS.

In a full mesh configuration, each router acts as a peer to all others, which facilitates a complete exchange of routing information. This is essential in IBGP because BGP does not propagate routes learned from one IBGP peer to another; hence, direct connections among all routers ensure that routing information is fully disseminated within the AS.

In contrast, other connection types, such as partial mesh and hub-and-spoke topologies, would result in some routers missing out on certain routing updates, leading to potential routing inconsistencies. These other options may involve selective connections or hierarchical routing, which do not provide the robustness or redundancy benefit that full mesh offers.