An IOS XE router has an Established BGP session to an Azure VPN gateway and is advertising the campus prefix. Hosts in the virtual network still cannot reach the campus. The subnet route table has no route for the campus prefix toward the gateway. What is missing?
Select an answer to reveal the explanation.
Short Explanation
BGP did its job and the virtual network's own map never pointed at the gateway. You add a route for the campus prefix in the subnet route table toward the VPN gateway. Another IKE proposal will not copy a BGP route into that table.
Full Explanation
An Established BGP session means Azure's gateway has the campus prefix. Hosts in a subnet do not use the gateway's BGP table directly. They use the subnet route table. With no route for the campus prefix toward the VPN gateway, their packets never enter the tunnel. Add that route. A second IKE proposal does not install subnet routes. The SA is already up enough for BGP to be Established. The Azure VPN gateway does not run OSPF and does not copy prefixes into a subnet route table that way. The BGP keepalive keeps the session alive. It does not write the subnet route table. Exam caveat: a user-defined route for the campus prefix must be more specific than a default that points somewhere else, or the default still wins. Operational check: the subnet route table should list the campus prefix toward the gateway, and a host should then reach the campus while the BGP session stays Established.