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Date: Mon, 27 Aug 2018 17:56:51 +0200
From: Kurt Jaeger <pi@freebsd.org>
To: rmacklem@uoguelph.ca, stable@freebsd.org
Subject: NFS via IPv6 between 11.2-REL amd64 and larger (>45 files)
 directories?
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Hi!

I've seen a strange effect: NFS via IPv6 between 11.2-REL amd64
boxes failed for directories with more than 45 files or directories.
Small directories worked. It seems to be an issue with
ipv6 fragmentation (?), as can be seen by tcpdump:

17:54:16.855978 IP6 nfs-serv > nfs-client frag (0|1448) 2049 > 709: NFS reply xid 1536109002 reply ok 1440 readdir
17:54:16.855979 IP6 nfs-serv > nfs-client frag (1448|36)

As soon as the NFS request is sent with fragments, it stalls.

Is this a known issue ?

-- 
pi@FreeBSD.org         +49 171 3101372              2 years to go !