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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: IP Fragmentation
On 25 aug 2008, at 12:27, Fernando Gont wrote: http://support.microsoft.com/kb/925280 IPv4 minimum MTU is 68 bytes, That's kind of like "a human being can live without food for four to six weeks". It's not a recommendation. 536 is the minimum fragment re-assembly buffer size. Falling back to 536-byte packets does not guarantee that sessions will be kept up. But: "PMTU black hole router detection is triggered on a TCP connection when TCP starts retransmitting full-sized segments with the DF flag set. TCP resets the PTMU for the connection to 536 bytes. Then, TCP retransmits its segments when the DF flag is clear."
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