Patent attributes
Techniques include quickly establishing a maximum transmission unit (MTU) for a network path, such as a network tunnel. In one example, data representative of the MTU is included in a header of a packet. If the MTU indicated in the packet is larger than a downstream network interface of a network device, the network device updates the data of the header to indicate the MTU of the downstream network interface, and an egress network device sends the packet back to an ingress network device. In another example, network devices fragment packets, if necessary, such that the fragments satisfy the MTU of the downstream network interface. The egress network device then determines the MTU for the path based on a largest received fragment, reassembles the fragments into a single packet, and returns the reassembled packet to the ingress network device. The packets may comprise echo packets of generic routing encapsulation (GRE).
