An engineer brings up underlay BGP on a new leaf but forgets to advertise the VTEP loopback into the fabric. What failure class does this misconfiguration create?
Select an answer to reveal the explanation.
Short Explanation
No advertisement for the VTEP loopback is like publishing a tunnel entrance with no street address. Underlay BGP can look fine on the links while overlays stay dark because nobody can route to that VTEP.
Full Explanation
Overlay VXLAN/EVPN requires underlay IP reachability to VTEP endpoints, typically loopbacks advertised into the fabric IGP/BGP. Omitting that advertisement is a common misconfiguration: link sessions may be up while tunnel endpoints remain unreachable. LLDP does not replace VTEP routing; both unicast and multicast overlays need VTEP reachability; ethertype bridging does not substitute for underlay host routes.