The Reassembly Failure counter displays a value that is higher than expected when you use the “netstat -s” command in Windows Vista
When you use the netstat -s command to display per-protocol statistics in Windows Vista, the Reassembly Failure counter displays a value that is higher than expected. The value from the Reassembly Failure counter may even be as high as the value from the Reassembly Successful counter.
For example, the “IPv4 Statistics” section of the netstat -s command output may resemble the following:
IPv4 Statistics Packets Received = 6268757 Received Header Errors = 0 Received Address Errors = 12517 Datagrams Forwarded = 0 Unknown Protocols Received = 2 Received Packets Discarded = 53576 Received Packets Delivered = 6403107 Output Requests = 3577979 Routing Discards = 0 Discarded Output Packets = 485 Output Packet No Route = 2 Reassembly Required = 3095 Reassembly Successful = 1534 Reassembly Failures = 1534 ------------>Not True Datagrams Successfully Fragmented = 2268 Datagrams Failing Fragmentation = 0 Fragments Created = 4539
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB949130.