After enabling VXLAN on the municipal fabric, operators see MTU blackholes for large tenant frames. What data-plane planning issue is most likely?
Select an answer to reveal the explanation.
Short Explanation
VXLAN wraps the original frame, so the outer packet gets bigger—like a letter plus a thick courier pouch. If the underlay MTU cannot fit that pouch, big civic frames quietly die on the road. Fix underlay MTU or MSS carefully; do not blame Type-2 route length for an MTU blackhole.
Full Explanation
VXLAN/UDP/IP encapsulation increases packet size relative to the original tenant frame. If underlay interfaces and paths remain at a standard 1500-byte MTU without accounting for overhead, large frames can be dropped—classic MTU blackholes. Best practice is to raise underlay MTU (often to jumbo sizes in DC fabrics) or carefully manage MSS/PMTUD behavior. Unicast and BUM encapsulated frames both consume the extra header bytes. EVPN route types are unrelated to Ethernet payload MTU blackholes.