JNCIP-SP: Juniper Networks Certified Professional – Service Provider (2023) — Question 32

Which two statements are correct about a sham link? (Choose two.)

Answer options

• A. The PEs exchange Type 1 OSPF LSAs instead of Type 3 OSPF LSAs for the L3VPN routes.
• B. It creates an OSPF multihop neighborship between two PE routers.
• C. It creates a BGP multihop neighborship between two PE routers.
• D. The PEs exchange Type 3 OSPF LSAs instead of Type 1 OSPF LSAs for the L3VPN routes.

Correct answer: A, B

Explanation

The correct statements are A and B because a sham link allows PEs to exchange Type 1 OSPF LSAs, which is necessary for proper route calculation in L3VPNs, and it indeed establishes an OSPF multihop neighborship between the PE routers. Options C and D are incorrect as they misrepresent the protocol used and the type of LSAs exchanged in the context of sham links.