amd64/164462: NFSv4 mounting fails to mount; asks for stronger authentication

[Joseph Lenox]

>Number:         164462
>Category:       amd64
>Synopsis:       NFSv4 mounting fails to mount; asks for stronger authentication
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-amd64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jan 24 23:50:14 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Joseph Lenox
>Release:        9.0-RELEASE
>Organization:
Southern Illinois University - Carbondale
>Environment:
FreeBSD <hostname> 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan 3 07:46:30 UTC 2012 root at farrell.cs.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64
>Description:
http://serverfault.com/questions/347163/mounting-nfsv4-share-from-debian-linux-6-to-freebsd-9-rc3-server-requires-stron

I've linked my problem from ServerFault, gist of it is as follows:

A FreeBSD 9.0-RELEASE box I have does not allow NFSv4 mounts from other machines on the network, nor to itself using sec=sys.

mount returns "mount_nfs: /path/dir, : Permission denied" when run from the server (attempting to mount a nfs-exported directory), no log entries that I can find. Attempting to mount from a Debian 6.0 box gives an "Access denied by server" message and "RPC: server requires stronger authentication" message in that machine's syslog. 

Using NFSv3 does work in that I can mount directories. 
>How-To-Repeat:
Set up a NFS share in /etc/exports or via ZFS, setting sec=sys as an option
Mount the share over the network using -o sec=sys,nfsv4. 
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: