[Samba] RPC server is unavailable

[Sonic]

Seems this issue is caused by a bug with the 'hosts allow' parameter
in a Samba4 AD.
I rebuilt the server again, did a successful classic upgrade yet still
had the same "The RPC server is unavailable".
The log.samba was showing these errors:
=====================
[2017/07/15 18:37:47.507683,  0] ../lib/util/access.c:361(allow_access)
 Denied connection from LOCAL/unixdom (LOCAL/unixdom)
[2017/07/15 18:37:47.507756,  0]
../source4/lib/socket/access.c:123(socket_check_access)
 socket_check_access: Denied connection to 'smbd' from LOCAL/unixdom
(LOCAL/unixdom)
=====================
A search turned up some hits going way back to early Samba4 days where
such errors were logged when using the 'hosts allow' parameter. I was
using the 'hosts allow' to limit the testing of the new AD on the
production network to specific systems and hopefully not expose the
whole network to the AD environment. The minute I removed the 'hosts
allow' line systems could join the new AD and the problem of "The RPC
server is unavailable" was gone.



On Sun, Jul 9, 2017 at 11:08 PM, Sonic <sonicsmith at gmail.com> wrote:
> I eliminated any possible problems caused by the samba_dnsupdate and
> did the classicupgrade directly on the remote system and still have
> the same problem:
> "The RPC server is unavailable"
>
> Everything looks right all tests in the wiki pass, the ports are open
> and yet... systems cannot join the domain.