Patent ID: 7451227

Claim:
A method for discovering a path maximum transmission unit (PMTU) among nodes on an Internet protocol (IP) network, comprising: at a node on the IP network, (a) comparing a size of a received packet with a maximum transmission unit (MTU) of a next link; (b) when the size of the received packet is greater than the MTU of the next link, generating an error message, transmitting the generated error message to a source node, generating a test message of the size of the MTU of the next link, and transmitting the generated test message to a destination node; (c) if the received packet is a test message generated by a previous node, storing MTU information, source address information and destination address information contained in the received packet; and (d) comparing the MTU information, source address information, and destination address information of a packet received after transmitting the error message generated in step (b) to the source node, with the MTU information, source address information, and destination address information stored in step (c), and when the information of the comparison is the same, discarding the received packet without generating an error message and a test message.