VXLAN MTU considerations

For VXLAN VPLS services, the network port MTU must be at least 50 Bytes (54 Bytes if dot1q) greater than the Service-MTU to allow enough room for the VXLAN encapsulation.

The Service-MTU is only enforced on SAPs, (any SAP ingress packet with MTU greater than the service-mtu is discarded) and not on VXLAN termination (any VXLAN ingress packet makes it to the egress SAP regardless of the configured service-mtu).

Note: The router never fragments or reassemble VXLAN packets. In addition, the router always sets the DF (Do not Fragment) flag in the VXLAN outer IP header.