MTU

Maximum Transmission Unit (MTU) specifies the maximum frame payload size that the Firewall Threat Defense can transmit on a given Ethernet interface. The MTU value excludes Ethernet headers, VLAN tags, or other overhead. For example, if you set the MTU to 1500, the expected frame size is 1518 bytes including the headers, or 1522 when VLAN tagging is used. Do not set the MTU value higher to accommodate these headers.

VXLAN and geneve encapsulation requirements

For Geneve, the entire Ethernet datagram is being encapsulated, so the new IP packet is larger and requires a larger MTU. Set the Firewall Threat Defense VTEP source interface MTU to the network MTU plus 306 bytes.