15.04 - Mounting using CIFS failing with "No such device or address"

Question

I'm trying to mount a cifs share using:

sudo mount \
    -t cifs \
    -o credentials=$HOME/.smbcredentials \
    //server.example.com/Common/Share/Path /mnt/mountpoint

Which fails with:

Retrying with upper case share name
mount error(6): No such device or address
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

Watching /var/log/syslog shows that there is some sort of dns problem:

Jun  4 18:06:12 laptop key.dns_resolver: DFSAPP03: No address associated with name
Jun  4 18:06:12 laptop kernel: [ 1807.650756] CIFS VFS: cifs_mount failed w/return code = -6

Does anybody know what the return code -6 means, or how I might go about debugging this problem?

Solution

Ok, it turns out that the problem was with the DNS resolution of the file server. It was trying to resolve the hostname "DFSAPP03" and failing. In my case the problem was fixed by using a different server address. The error:

cifs_mount failed w/return code = -6

Probably indicates that while the authentication steps are all OK, these is a problem with actually finding the share on the network.