Please see this post for details of the Samba4 and NFS installation on Ubuntu. The current post uses the client server details from there.
1. Ubuntu
Server
We have to change the export slightly to get the automount to recognise the domain entry, CACTUS in this case, so we must export it.
note
please be careful with line breaks if you are copying from here. I'll convert the text so that it fits onto a single line but I can only guarantee that in my browser (Chromium under LXDE on openSUSE)
edit /etc/exports
/home/CACTUS *(rw,sec=none:sys:krb5:krb5i:krb5p,no_subtree_check,insecure)
Client
sudo apt-get install autofs
edit /etc/auto.master
/home/CACTUS /etc/auto.misc
edit /etc/auto.misc
* -rw,sec=krb5,vers=3 /home/CACTUS/&
Finally, restart the automounter:
service autofs restart
2. openSUSE
Same as Ubuntu except that it's already installed and to restart it's:
rcautofs restart