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Old 07-03-2014, 03:17 AM   #1
vjramana
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Can't ping to our server from another department


We are small group in a university. We have our own router (using Linksys E42000) to prevent unwanted external access to our servers. But we can connect to internet.

By the way we have three linux servers in our group which need to be accessed from outside our group, mainly using ssh.

Question:
Do I need to give permission to my router so that I ca connect to our linux server in our group from outside?

If yes, what is the procedure to do so?

We use internal static IPs to our linux servers.
 
Old 07-03-2014, 09:55 AM   #2
TB0ne
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Quote:
Originally Posted by vjramana View Post
We are small group in a university. We have our own router (using Linksys E42000) to prevent unwanted external access to our servers. But we can connect to internet. By the way we have three linux servers in our group which need to be accessed from outside our group, mainly using ssh.
Very similar to a question you asked two years ago:
http://www.linuxquestions.org/questi...tu-4175419881/

Unless you have a route between the two different networks, you won't be able to get access. If you can't ping them, that MAY (or may NOT) be a problem, since your router/firewall may be blocking ICMP packets. You don't say anything about the network(s) in question, so there's not much we can say.
Quote:
Question:
Do I need to give permission to my router so that I ca connect to our linux server in our group from outside? If yes, what is the procedure to do so? We use internal static IPs to our linux servers.
The procedure would be for you to read the manual that came with your router, to determine how to allow traffic on the port(s) in question. Since you can run SSH on pretty much any port, and you don't say what port it IS running on, we can't tell you.
 
Old 07-03-2014, 10:10 AM   #3
suicidaleggroll
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It sounds like a typical port forwarding issue. Your servers are not on the same network as the rest of the University, they're on their own subnet controlled by your router. When you type in your server's IP on a machine outside of your little local subnet, it has no idea how to access that IP, so it asks its DNS server, which doesn't know either, and you get a failed connection. You need to connect to your ROUTER's IP from any external machine, and then tell your router what to do with those incoming packets. If you want to ssh in to the three machines, then you'll need to set up three unique ports and then set up port forwarding in the router to push each port to its machine.

For example, if your three servers are:
192.168.1.2
192.168.1.3
192.168.1.4

And your university is on the 10.1.10.* subnet
And your router's public IP is 10.1.10.234

You could set your router to forward incoming packets on:
port 10002 to 192.168.1.2:22
port 10003 to 192.168.1.3:22
port 10004 to 192.168.1.4:22

Then from any other machine on the University network, you would ssh to 10.1.10.234 on either port 10001, 10002, or 10003 to access your three machines.

Of course replacing these port numbers with anything you feel like between 1025 and 65535, and replacing the IPs with their actual values.

Last edited by suicidaleggroll; 07-03-2014 at 10:11 AM.
 
  


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