Why does this happen?

[kovax]

i have a server that i can not ssh to.
example- when i am at home i can ssh to a remote server with no problems. however, when i am at work and i ssh to my machine at home and then try to get to the remote server i can not.
What does this mean? is it a routinig issue?

Thanks

[Void Main]

Let me get this straight. You have a machine at home (machine "A"). You can ssh from machine "A" to a remote server "B". When you are at work on machine "C" you can ssh into machine "A" but while sshed into machine "A" you can't ssh to machine "B" from machine "A"? There is no reason this should happen that I can think of, I do it all the time. Can you ping or traceroute to machine "B" from "A"?

Now, if you are trying to hop directly through "A" to get to "B" (non-interactively) then you'll have to add add a "-t":

[machineC]$ ssh -t -x user@machineA ssh -x user@machineB

[kovax]

It is just weird that when at home i can hit machine B with no issues.
History- What I want to do is administer Machine B from Machine C. I cant ping Machine B from Machine A nor Machine C. The quick fix was for me to PCanywhere to a box on my home network and then ssh to Machine B. The ultimate goal is to get to machine B from both machine A and machine C.
I know this seems strange but it would help me out a lot.
Thanks!

Let me get this straight. You have a machine at home (machine "A"). You can ssh from machine "A" to a remote server "B". When you are at work on machine "C" you can ssh into machine "A" but while sshed into machine "A" you can't ssh to machine "B" from machine "A"? There is no reason this should happen that I can think of, I do it all the time. Can you ping or traceroute to machine "B" from "A"?

Now, if you are trying to hop directly through "A" to get to "B" (non-interactively) then you'll have to add add a "-t":

[machineC]$ ssh -t -x user@machineA ssh -x user@machineB

[Void Main]

It's not strange. Like I said, I do this all the time and I don't understand why it doesn't work for you now. You didn't indicate whether the command I suggested worked:

[machineC]$ ssh -t -x user@machineA ssh -x user@machineB

If you can "PCAnywhere" to machineA and from there ssh to machineB then you should be able to just "ssh" to machineA and from there ssh to machineB which is what I thought you said you couldn't do. It doesn't compute. If you want to be able to get directly to any of the three machines from any of the three machines then I need to know more about your network setup on all machines and anything in between (network addresses, gateway addresses, firewalls, etc).

[kovax]

I ran the command that you suggested but it times out i beleive when i try to connect to machine B.
I actually get to login when i hit machine A but i time out eventurally.

[Void Main]

Ok, so it won't let you hop through directly but it will let you hop through interactively?

Code: Select all

[machineC]$ ssh user@machineA
[machineA]$ ssh user@machineB
[machineB]$


Are all three running Fedora and stock openssh? What versions? I would still need a network map and your IP configurations if you want help figuring out why machineC cant talk to machineB directly. You can send this in a PM if you don't want the IP information known.

[worker201]

I don't know if this will help or not, but when I was setting up my ftp server, Void and I discovered that incoming access was blocked. Machines on the university net could access ftp, but machines outside it could not. So I had the reverse problem - I could access from work, but not from home.

The solution was amazingly simple - contact campus network security and ask them to allow ftp traffic to my server. After a day of checking to make sure security on the ftp machine was tight, they granted access.

I hope that such a simple yet easy to overlook thing is not your problem here.

[kovax]

Void-
My servers config is
MachineA= RedHat 9
MachineB= Fedora Core 2
MachineC= Windows2K (dont laugh it is my work machine and I work with both operation systems).

[Void Main]

Once Logged in to MachineA do you get any error messages when you try to log into MachineB from it? Those would be helpful. In fact add "-vv" to your ssh command line so you get verbose output which should indicate what the problem is.