Patent ID: 8422501

Claim:
A method comprising: storing, in a first maximum transmission unit (MTU) table, a first set of MTU values each corresponding to one of a plurality of first-hop routers associated with a sending host; identifying a first-hop router of the plurality of first-hop routers, wherein the first first-hop router is on a network path that comprises the sending host, the identified first-hop router, and a destination host; determining whether a second MTU table includes an entry corresponding to the destination host; in response to a determination that the second MTU table does not include an entry corresponding to the destination host: determining, from the first MTU table, a first MTU value corresponding to the identified first-hop router; generating a first packet of a size defined by the first MTU value; begin transmitting the first data packet through the network path to the destination host; receiving a notification that the first data packet failed to reach the destination host, wherein the notification indicates that a required path MTU value for the network path is smaller than the first MTU value; and in response to receiving the notification that the first data packet has failed to reach the destination host, storing, in the second MTU table, the required path MTU value as associated with the destination host, wherein the second MTU table contains only MTU values corresponding to one or more individual destination hosts for which an associated required path MTU value from the sending host to the one or more individual destination hosts is smaller than the MTU value for the first-hop router used to reach each of the one or more individual destination hosts, and wherein the first MTU table and second MTU table are maintained by the sending host.