I have a very strange problem with my new router and OpenSSH. If I do for example "ls -R" on the remote machine, I get some text and then SSH output "freezes" until I press a key on the keyboard. Putty doesn't have this problem on neither Linux nor Windows machines. Nor does it happen if I use my old router.

I've tried "KeepAlive yes" & "TCPKeepAlive yes" on sshd_config on the remote machine, and "ServerAliveCountMax 3" & "ServerAliveInterval 1" on ~/.ssh/config and /etc/ssh/ssh_config on the local machine. Nothing seems to help.

Any ideas?

Well, if ALL you changed was the router, that certainly points to the root of the issue. Did you make any changes/modifications to the old router or its configuration? And what kind of routers are you talking about?

I had some port forwardings, but I have the same forwardings in this new router. Also, they only deal with incoming connections, so I don't think they have anything to do with outgoing SSH-connections, they shouldn't anyway. The old router was Thomson TG784 and the new one in Inteno DG301AL, they are both provided preconfigured for my DSL by my ISP.

You're right...the incoming forwardings won't bother the outgoing ones. I'm sorry to say I've never heard of either of those brands, but if they're pre-configured by the ISP, I have to wonder if their tech support folks wouldn't know something about it? Perhaps you got a flaky unit, or there's some setting they need to change on their side?

Yeah, I have already contacted my ISP and they're trying to fix it, but I wouldn't hold my breath... I was just wondering if someone else had run into a similar behaviour

The only time I had run into that was on a WAN, years ago. But, we controlled both sides of the link, and adjusting things on the router (and on the server), got it going again. But if all you changed was your router, that makes it suspect. Unless, there was a REASON you got a new router...did they 'upgrade' your service, by any chance? Did you change providers?

Hi,

Perhaps you can have a look at the router logs or the firewall logs if any. You can even try upgrading the firmware on the router also. Just a suggestion

My ISP agreed to replace the router, so perhaps a new unit will work. I'll let you know when I receive it The router was originally replaced because I was experiencing some speed issues with the old one. My ISP determined that it was because of the old age of my old router. I.e. there was no upgrade or anything like that, just a new router.

I don't think the router kept any logs, but I'll see that when the new unit arrives if the problem persists. The firmware was already upgraded to the latest version by the ISP (in fact they're running their own firmware in the routers to begin with and there is no possibility for the user to upgrade it).

Well... My ISP replaced the modem/router with a similar unit, which had exactly the same problem. Unfortunately this was the only modem/router they had available(?!), so in the end I had to get my own. The new one I got (TeleWell tw-eaw510 https://www.telewell.fi/en/product/a...V510/tw-eav510) works perfectly. No sign of any ssh- or any other problems. I get 22/2.2 Mbps speeds on my ADSL-line, which is very decent.