autofs 5.1.3 attempts communication with portmapper (port 111) even for NFS4 mounts
This document (000020650) is provided subject to the disclaimer at the end of this document.
SUSE Linux Enterprise Server 12 SP5
Normally, this would not cause any problem because local port 111 is typically reachable. However, if an ssh tunnel (or some other feature) causes traffic on a local IP address to be fowarded to a remote system, firewalls or limitations of the tunnel configuration could block attempts to reach the remote port 111.
1. Necessary syntax:
Include the nfs mount option "port=2049" in the automount map. Automount maps can be done in many ways, so the exact method may vary, but here is one example of including mount options within the /etc/auto.master entry of a direct map:
/- /etc/auto.direct nobind,rw,vers=4,port=2049,proto=tcp
2. Autofs patch:
For SLES 12 SP5, the change was introduced in autofs 5.1.3-3.8.1, released in public maintenance April 19, 2022.
For SLES 15 SP3, a change was introduced in autofs 5.1.3-150000.7.11.1, released in public maintenance April 26, 2022.
In SUSE's autofs changelog, the fix appears as:
Suppress portmap calls when port explicitly given
The patches were described upstream changelog as:
- remove some redundant rpc library code.
- add port parameter to rpc_ping().
- dont probe NFSv2 by default.
- add version parameter to rpc_ping().
And the patches also included this description:
Add an version parameter to rpc_ping() to try and avoid NFS pings
to protocol or NFS version that isn't to be used.
When the port option is specified (possibly for NFS tunneling) it's
likely that the protocol is also specified which will reduce unneeded
NFS ping requests. But for this to work best (with the minimum delay)
the NFS version needs to also be specified in the NFS mount options.
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- Document ID:000020650
- Creation Date: 04-May-2022
- Modified Date:04-May-2022
- SUSE Linux Enterprise Server
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