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Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU
- From: Iljitsch van Beijnum
- Date: Sun Jan 09 18:41:11 2005
On 10-jan-05, at 0:08, Mark Andrews wrote:
Well DNS (not EDNS) is limited to 512 octets so you unless there
are real links (not ones artificially constrained to demonstrate
a issue) this should not be a issue in practice.
No, fortunately not. But it's still VERY wrong and it must be fixed.
In IPv6 PMTUD is handled at the IP layer so the second packet that's
too large will be fragmented at the source, so there is no issue.
Note for IPv6 one sets IPV6_USE_MIN_MTU on the UDP socket so this
should be a non-issue there.