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Centos 5 / Samba / DNS

Posted: 2019/02/06 21:05:49
by broken_admin
I just inherited a problem on an EOL Centos 5 server.

There are two servers involved in this problem. Centos/Samba Server and Windows/AD/DNS server.

Windows mounts shares on the Samba Server.

Here is the problem.

Samba cannot ping the Windows server.
Windows cannot ping the Samba server.

Both servers are on the same subnet and on the same switch.

They can both ping all other devices on the network.

Both can reach the internet.

Samba get's it's DNS from Windows.

I created a forward zone on a remote Windows server in DNS to test DNS for Samba ... and it works fine. (just temporarliy changed /etc/resolv.conf)

On the Samba server, the network interface is a bridge - but it only has eth0 associated with that bridge.
I can change that - but I don't see the point since I can see the rest of the network.

I have changed ports on the switch (to eliminate this from my list of possibilites) it had no impact.

I have rebooted the Samba Server - after trying various service restarts.
All firewalls are off.

My last clue is that ssh connections take forever after you enter your password.
I am working on the console of the Samba server so I have direct access,
Has anyone seen this before? I am not finding anything similar in online searches.

Thanks for any ideas.

Yes - I know this needs upgraded to the new OS - but as I said, I just inherited this server when they called in the problem.

Re: Centos 5 / Samba / DNS

Posted: 2019/06/07 11:53:16
by holdenger
After pinging, check arp table on both systems, is there any entry? If the answer is yes... Are the mac addresses correct?


Code: Select all

arp -a

Code: Select all

arp -an | grep ""

Re: Centos 5 / Samba / DNS

Posted: 2019/06/07 16:33:42
by MartinR
There's something at the back of my mind about the slow ssh. IIRC I had a problem like this which was due to IPv6 running. Try using ssh -v.

Re: Centos 5 / Samba / DNS

Posted: 2019/06/07 17:09:23
by TrevorH
My last clue is that ssh connections take forever after you enter your password.
That's most likely a DNS config error. Out of the box sshd is configured to do reverse lookups on all ip addresses that connect to verify their names. If you DNS server is broken or slow or wrong then it will wait for 30s for a response and then move onto the next server listed in /etc/resolv.conf. If it tries all of them and none of them work then access is allowed but you'll get an error in your logs I think.

However, we are all responding to a 4 month old thread that's probably been solved/ignored by now. And about an o/s that's been EOL for more than 2 years and on life support for 3 years prior to that...