From: Christof Koehler <christof.koehler@bccms.uni-bremen.de>
To: autofs@vger.kernel.org
Subject: autofs reverts to IPv4 for multi-homed IPv6 server ?
Date: Thu, 7 Apr 2016 16:19:06 +0200 [thread overview]
Message-ID: <20160407141906.GU15153@bccms.uni-bremen.de> (raw)
Hello everybody,
I am on ubuntu 14.04 with autofs 5.0.7 and I observe an (for me)
unexpected behaviour as detailed below. Apparently using autofs NFS4
mounts fall back to using IPv4 addresses although valid IPv6 addresses
are available under certain circumstances, while a plain mount works as
expected.
Setup:
------
Both, NFS server and client, are configured with an IPv4 address and an
IPv6 GUA and IPv6 ULA. For brevity I will shorten the IPv4 address to
192, the GUA to 2001 and the ULA to fd5f below. I will only change the
DNS AAAA record in the following, the network configuration on
server/client or the A records never change. Server and client have
always working IPv4 and IPv6 GUA and ULA.
Test with mount:
----------------
Using a plain "mount -t nfs4 server:/locals /mnt/disk1/" on the client
gives depending on the DNS entries for the server the expected
source/target selection:
Server DNS entry| client address used to mount
2001 | 2001
fd5f | fd5f
2001+fd5f | fd5f
So in all cases RFC 6724/3484 is observed selecting the addresses.
Please note that the server has two AAAA records (multi-homed) in the
last test.
Test with autofs:
-----------------
A map lookup will yield "-fstype=nfs4,rw,intr,nosuid,soft,nodev server:/locals"
for the mount. Now I change again the servers AAAA records with the
following result:
Server DNS entry| client address used to mount
2001 | 2001
fd5f | fd5f
2001+fd5f | 192
For a multi-homed NFS4 server autofs apparently falls back to IPv4
although valid IPv6 options exist. As shown above just mounting without
autofs would stick to RFC 6724/3484 instead. I believe that autofs should
also select fd5f ULAs in the multi-homed case.
Is this a known behaviour ? Do any workarounds exist ? I could not find
anything.
I tried to compile autofs 5.1.1 with --with-libtirpc because
of https://bugs.launchpad.net/ubuntu/+source/autofs/+bug/1101779 but
could not get the binary to work. I filed a bug report for the behaviour
described above https://bugs.launchpad.net/ubuntu/+source/autofs/+bug/1564380
but suspect that this is better suited for this list.
Best Regards
Christof
--
Dr. rer. nat. Christof Köhler email: c.koehler@bccms.uni-bremen.de
Universitaet Bremen/ BCCMS phone: +49-(0)421-218-62334
Am Fallturm 1/ TAB/ Raum 3.12 fax: +49-(0)421-218-62770
28359 Bremen
PGP: http://www.bccms.uni-bremen.de/cms/people/c_koehler/
--
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next reply other threads:[~2016-04-07 14:19 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-07 14:19 Christof Koehler [this message]
2016-04-08 4:46 ` autofs reverts to IPv4 for multi-homed IPv6 server ? Ian Kent
2016-04-08 10:10 ` Ian Kent
2016-04-08 10:14 ` Ian Kent
2016-04-08 12:25 ` Christof Koehler
2016-04-08 14:29 ` Christof Koehler
2016-04-08 15:32 ` Christof Koehler
2016-04-10 2:09 ` Ian Kent
2016-04-08 16:12 ` Christof Koehler
2016-04-08 16:15 ` Christof Koehler
2016-04-10 2:17 ` Ian Kent
2016-04-10 2:14 ` Ian Kent
2016-04-09 1:42 ` Ian Kent
2016-04-09 9:56 ` Christof Koehler
2016-04-10 2:29 ` Ian Kent
2016-04-25 4:40 ` Ian Kent
2016-04-25 15:06 ` Christof Koehler
2016-04-26 1:06 ` Ian Kent
2016-04-26 9:53 ` Ian Kent
2016-04-26 15:27 ` Christof Koehler
2016-04-27 1:54 ` Ian Kent
2016-04-27 2:27 ` Ian Kent
2016-04-27 16:52 ` Christof Koehler
2016-04-28 2:56 ` Ian Kent
2016-04-28 3:21 ` Ian Kent
2016-04-28 9:12 ` Christof Koehler
2016-04-28 9:10 ` Christof Koehler
2016-04-28 10:50 ` Ian Kent
2016-04-28 11:26 ` Christof Koehler
2016-04-28 12:40 ` Christof Koehler
2016-04-29 1:54 ` Ian Kent
2016-04-29 14:10 ` Christof Koehler
2016-04-29 14:42 ` Christof Koehler
2016-04-30 3:21 ` Ian Kent
2016-04-30 11:36 ` Christof Koehler
2016-04-30 15:15 ` Christof Koehler
2016-04-30 15:16 ` Christof Koehler
2016-05-02 6:01 ` Ian Kent
2016-05-02 16:08 ` Christof Koehler
2016-05-03 7:58 ` Ian Kent
2016-05-03 15:13 ` Christof Koehler
2016-05-04 7:20 ` Ian Kent
2016-05-04 12:38 ` Christof Koehler
2016-04-09 1:35 ` Ian Kent
2016-04-11 2:42 ` Ian Kent
2016-04-11 16:32 ` Christof Koehler
2016-04-11 16:35 ` Christof Koehler
2016-04-12 1:07 ` Ian Kent
2016-04-08 11:47 ` Christof Koehler
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