Cannot connect SSH to CentOS 7.

Support for security such as Firewalls and securing linux
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sombre1
Posts: 6
Joined: 2016/03/19 23:01:43

Cannot connect SSH to CentOS 7.

Post by sombre1 » 2016/03/19 23:08:38

I have recently install a CentOS 7 virtual machine host and cannot connect to it from a Linux laptop. I can connect fine if I connect from a Windows 7 laptop with PuTTY. I have some tight fiewalld, xinetd, and fail2ban rules, but, I stop all three and I still cannot connect. I changed the IP on the laptop too to rule out that IP address being blocked somehow. I bring down the firewall on the client and that has no effect as well.

What happens is is that the connect hands and then eventually times out. Does anyone have any perspective on this?

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dmunk
Posts: 37
Joined: 2016/03/16 03:33:49

Re: Cannot connect SSH to CentOS 7.

Post by dmunk » 2016/03/20 15:21:41

What does the client say when you use the "-vv"? Like :

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ssh -vv user@some_host
Also, since your on 7, try doing the below on the target host being connected to :

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journalctl -f -u sshd.service 
I would try connecting from a know good host " the working windows putty box" and the non-working laptop while tail the above log detail. You will see the putty session and then the failure of the laptop. Should get you some info to make an informed decision with.

dmunk

aks
Posts: 2891
Joined: 2014/09/20 11:22:14

Re: Cannot connect SSH to CentOS 7.

Post by aks » 2016/03/20 17:50:05

Maybe the Windows firewall is blocking it (or any routers/filters in the network path)?
Or as dmunk hinted at, perhaps sshd is not running?

sombre1
Posts: 6
Joined: 2016/03/19 23:01:43

Re: Cannot connect SSH to CentOS 7.

Post by sombre1 » 2016/03/21 18:23:52

Thanks guys. With the verbose logging I was able to track it down to an issue with the wireless on the client. When I use a LAN connection it works fine.

I will play around with it and, if needed, open up a new thread.

Thanks again.

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