SSH Issue

Issues related to configuring your network
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Posts: 3
Joined: 2005/10/28 18:43:30

SSH Issue

Post by Pryach » 2005/10/28 19:29:14

I use Putty and WinSCP to manage two web servers, one is owned by HiVelocity, the other by ev1 (I think, it's a shared hosting with SSH access). The HiVelocity server is CentOS 4.2 and the ev1 server is Redhat (can't remember which version off the top of my head).

From home, I can connect to the ev1 server and leave putty and WinSCP open for however long I want, days. However, with HiVelocity, SSH times out after about 10 minutes of inactivity.

From work, I can connect to the ev1 server and leave putty and WinSCP open for however long I want, days. With HiVelocity, I can connect and leave putty and WinSCP open for however long I want, days.

Why does HiVelocity not stay open when I am home? I don't see how I could be a problem with my computer/ISP, since I'm able to maintain a connection with ev1. This is what HiVelocity said:

We have checked on our end and we cannot find anything as of yet. Some other techs are suggesting that it could be a possible intermitten ISP issue. As far as you connecting to the other hosting company; by looking at the tracerts you have posted, it looks as though your ISP routes you much differently to us. and them. Please ask your ISP to check on their end as well. Let us know what their results are.[/quote]

Here is the traceroutes they are referring to:

Does anyone have any other ideas, or maybe what I could ask my ISP?

I asked at a dedicated server site and someone mentioned they had the same problem with CentOS 4 and I was wondering if this is some kind of known issue?

ClientAliveInterval and ClientAliveCountMax in my SSH config are both commented out.

Posts: 22
Joined: 2005/09/16 18:38:28

Re: SSH Issue

Post by Wolf-R1 » 2005/11/01 15:11:54

You call that a problem???

That's how I would configure my connections. Idle connections get timed out after X number of minutes. There's no way I'd allow connections, especially public Internet based conns, to stay open for that long.

Other than that tidbit I'd check out the /etc/ssh/sshd_config file to see what's in there. Either there's a time out in there or if there's a firewall that you have to traverse prior to your SSH server then that could be timing out your connection if it's idle.

Posts: 16
Joined: 2005/06/22 10:44:35

Re: SSH Issue

Post by foobar47 » 2005/12/14 13:38:02

Yeah, it's normal and it should always be like that...

And, one more thing, "commented out" is not "not configured" !!

Posts: 14
Joined: 2005/04/27 18:01:39

SSH Issue

Post by dcpaq2 » 2006/05/27 02:15:23


I have the same issue, I realize that its not always safe to leave an ssh connection open for too long inactive. But mine is timing out as well after EXACTLY 10 minutes and I would like to find out what is causing this so that I can put a stop to it, or at least increase it to 30 or 45 minutes. Sometimes Im researching things and while i am doing that my connection is getting closed out.

My server use to have Red Hat Enterprise WS on it and I never had this issue, but now I am using Cent OS 4.2 and I have this problem.

Its been a big headache trying to figure out if its my ISP (comcast) provider or router (linksys WRT54G) or Windows XP firewall, as I have changed ISP between the times I changed operating systems on my server and I have changed routers between those times as well, so i just cannot figure out what is causing this.

Again I know that increasing the time is a security risk and most dont want to increase it but is there anyone who might be willing to try and help me out here?



Posts: 14
Joined: 2005/04/27 18:01:39

Re: SSH Issue

Post by dcpaq2 » 2006/05/27 02:17:45

Please delete, accidentally refreshed the screen and it double posted.

Posts: 1927
Joined: 2006/04/20 19:03:33
Location: Montreal/QC

Re: SSH Issue

Post by foxb » 2006/05/29 13:54:24

It should be somewhere into route (probably statefull firewall(IPS) reseting inactive connections).

I can leave ssh in my local network for many hours (CentOS 4.3 + default config).

Are you able to see the logs on CenOS machine?

Posts: 20
Joined: 2006/03/07 18:01:26

Re: SSH Issue

Post by cestokes » 2006/06/26 15:33:08

Not sure if you've tried it yet, but this has worked for me in the past.

PuTTY has an option in Connection menu named "Sending of null packets to keep session active"

Maybe try setting that as 60 (one keepalive every 60 seconds) and see what happens?

Posts: 34
Joined: 2006/07/05 18:51:49

Re: SSH Issue

Post by danstoner » 2006/07/05 20:22:36

The setting seems to be configurable in /etc/ssh/ssh_config


I did not confirm but found it using google.

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