IP报文分片技术及其在故障分析中的应用

TCP/IP协议采用分片机制来解决传输层报文与MTU的适配问题及适应传输链路上MTU的变化,但传输层大包产生的连续分片会引起与分片相关的新问题,在网络建设和运行中这类问题往往被忽视。结合某专有网络实际应用中的典型分片相关故障,在对IP报文分片的机理和不同网络设备的分片处理机制差异性简单介绍的基础上,重点分析了故障机理并给出了相应处理措施。测试结果表明：这些措施可有效解决和预防与分片有关的故障,提高了网络的可用性。

IP Message Fragment Technology and Its Application in Fault Analysis

The fragment mechanism is used in TCP/IP protocol to solve the adaption problems of message and MTU in transport layer and adapt to the changes of MTU in the transmission link. However, the continuous fragment produced by package in transport layer can cause the new problems relevant to the fragment. These kinds of problem are often neglected in network construction and operation. Combining with the relevant faults of typical fragments in the real application of proprietary network, this paper briefly introduces of the differences between IP message fragment mechanisim and fragment handling mechanisim of different network devices,and intensively analyzes the fault mechanism and gives the revelent treatment measures. The test results show that such measures can effectively solve and prevent the faults relevant to fragment, and improve the availability of network.