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Re: IP Fragmentation
At 07:07 p.m. 20/08/2008, Sam Stickland wrote:
Yet all OSes have it enabled and there is no fallback to fragmentation in PMTUD: if your system doesn't get the ICMP messages, your session is dead in the water.Windows Vista/2007 has black hole detection enabled by default. It's not massively elegant, but it will keep sessions up (falls back to 536 byte MTU).
IPv4 minimum MTU is 68 bytes, not 536. 536 is the minimum fragment re-assembly buffer size. Falling back to 536-byte packets does not guarantee that sessions will be kept up.
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