Centos 6 cannot ssh externally?

newbie14 · 01-03-2012, 11:29 AM

Dear All,
I have just installed centos 6. I would like to ssh to the machine. So I have checked ssh service is running, firewall allows port 22, iptables also allow port 22 and also disabled SELinux. With all these I cannot still ssh from externally. But locally when I just telnet 192.168.1.5 22 I get the ssh message. Why I cannot do it externally even though I have set the port forwarding to the machine? Any steps I am missing?

snowday · 01-03-2012, 11:31 AM

Start the sshd service.

newbie14 · 01-03-2012, 11:32 AM

Dear Snowpine,
I have checked the status service sshd status it shows me running with a particular pid.

snowday · 01-03-2012, 11:33 AM

What is the error message?

newbie14 · 01-03-2012, 11:34 AM

Dear Snowpine,
When I telnet from local ip is ok, from eternal ip it like trying to connect and just close no error message.

repo · 01-03-2012, 11:35 AM

Are you trying to connect from the outside from your LAN, or do you connect from the inside to the outside and back in?
Some routers don't support this.
Any error messages?

Kind regards

snowday · 01-03-2012, 11:36 AM

telnet is not ssh

http://www.centos.org/docs/5/html/De...nt-config.html

newbie14 · 01-03-2012, 11:38 AM

Dear Repo,
Yes I trying to connect back into the LAN using dynamic ip of the LAN. But is still the same connection just trying to go outside and come back in.Where to check the edit message it just close the terminal?

repo · 01-03-2012, 11:43 AM

Try from the outside.
You can use an online portscanner to see if por 22 is answerig.
http://nmap-online.com/

Kind regards

newbie14 · 01-03-2012, 11:51 AM

Dear Repo,
Below is the results. So what does this translates into?

Nmap Options: -p22-23 -T4 -sS 124.82.40.118

Starting Nmap 4.75 ( http://nmap.org ) at 2012-01-03 18:47 Central Europe Standard Time
Note: Host seems down. If it is really up, but blocking our ping probes, try -PN
Nmap done: 1 IP address (0 hosts up) scanned in 2.62 seconds

repo · 01-03-2012, 11:53 AM

Quote:

Note: Host seems down. If it is really up, but blocking our ping probes, try -PN

Does your firewall/router blocks ping requests?
Try to use the

Code:

-PN

option.

Kind regards

newbie14 · 01-03-2012, 11:56 AM

Dear Repo,
The latest results is below

Nmap Options: -p22-23 -PN -T4 -sS 124.82.40.118

Starting Nmap 4.75 ( http://nmap.org ) at 2012-01-03 18:56 Central Europe Standard Time
Interesting ports on 82.124.in-addr.arpa.tm.net.my (124.82.40.118):
PORT STATE SERVICE
22/tcp filtered ssh
23/tcp filtered telnet

repo · 01-03-2012, 11:59 AM

Could it be your provider is blocking ports?
Try to set ssh to another port (2222 or something higher)

Kind regards

newbie14 · 01-03-2012, 12:03 PM

Dear Repo,
I do not think my provide is blocking this port. So you want me to change the sshd to listen to different port is it?

repo · 01-03-2012, 12:07 PM

Quote:

So you want me to change the sshd to listen to different port is it?

Yes, try 2222
Don't forget the forwarding on the router, and to adjust the firewall if needed.

Kind regards