You are using E8GP peering in an underlay IP fabric.

Understanding EBGP in an IP Fabric:

EBGP (External Border Gateway Protocol) is commonly used in IP fabrics to establish peering between routers, such as leaf and spine nodes, without relying on an Interior Gateway Protocol (IGP) like OSPF or IS-IS.

IGP Requirement for EBGP:

Option B:EBGP peering does not require an IGP for adjacency establishment. This is because EBGP peers are typically directly connected, and BGP establishes its own sessions without needing an underlying IGP.

Leaf-to-Spine Peering:

Option C:In a typical IP fabric, each leaf node establishes an EBGP session with every spine node. This ensures full connectivity between leaves and spines, facilitating efficient routing and forwarding within the fabric.

Conclusion:

Option B:Correct—EBGP does not require an IGP for establishing peering sessions.

Option C:Correct—Each leaf node peers with every spine node, which is a standard practice in IP fabrics to ensure connectivity and redundancy.