Frequent disconnects on new superhub if I pause while logged through to remote machine using SSH.

[aaronsloman]

I have just acquired a new netgear (virginmedia) superhub which I was told would be equivalent to my old cable modem plus dlink router, but faster (30Mb/s instead of 20mb/s).

It is faster -- both cable and wireless connections, and upload speed is now at last (just) over the 1mb/s level.

But after using the system for a few hours I have found it terrible: I do a lot of work logged through to a machine at the university using ssh in a linux xterm window. It's fine while I type but if I stop to think, look something up, answer the phone etc I get logged out. This is very annoying and a dreadful waste of time.

Do these devices have a time-out mechanism that is adjustable? I've searched through the advanced menu three times and found nothing.

Is the problem the superhub or something at the far end of the cable that assumes I don't need the ssh connection any more if use stops for more than a few minutes. I could previously leave it logged in for hours at a time while I was working intermittently. If this can't be fixed I'll have to go back to the old equipment despite its slower speed.

This fault does not affect normal internet use -- browsing etc: I don't lose the ability to select a new web page, or even to repeat the ssh login.

Has anyone else experienced this?

[aaronsloman · Accepted solution]

After wasting time on a long phone conversation with a member of VirginMedia technical support staff who had great difficulty understanding the problem because he apparently had never heard of SSH, or logging through to another machine (I wonder how much that cost VM?) I consulted colleagues and the internet.

I discovered that there are several web sites where users of internet services complain about hubs that cause SSH connections to time out (although this never happened to me before I upgraded to Superhub).

The Superhub URGENTLY needs an option enabling users to adjust time-out periods for inactive connections: the current default seems to be a few minutes, which is quite intolerable.

For linux users like me the solution is either to expand the 'ssh' command using flags something like these (where the numbers refer to seconds)

 -o ServerAliveCountMax=1000 -o ServerAliveInterval=10

or else in the SSH configuration file

   ~/.ssh/config

add something like this

   # Site-wide defaults for various options

   Host *

    ServerAliveCountMax 600

    ServerAliveInterval 10

I expect Mac users have a similar option. I haven't a clue what a Windows user would have to do

as I never use windows for my work.

Aaron

http://www.cs.bham.ac.uk/~axs

[aaronsloman]

This is just to confirm that after I altered my SSH (Secure Shell) configuration (running linux on desktop machine and laptop) a couple of days ago the secure hub has worked perfectly, non-stop. Both my desktop machine and laptop consistently get reports of download speeds around 30mb/s as expected and upload as 1mb/s (as feared!).

The only problem is that if I want to connect an older laptop with older wireless card I have to re-set the superhub to 2.4Ghz and then the laptops cannot get above about 20mb/s. The Superhub, as someone has already pointed out, is inferior to other wireless routers that can handle both the old and new standards. I may have to buy a new high speed external wireless dongle for the old laptop.

My wife uses Windows XP connected via a long cable to the hub and she also finds the service perfect -- and noticably faster than before the upgrade.

Am I now the only satisfied customer? We are in the Birmingham area (B29).

(Actually not totally satisfied: if the Superhub had had a menu option to adjust the time out interval for connections like ssh it could have saved me many hours of wasted time on the first day -- including talking to a VM service person (apparently in another country) who obviously wanted t be helpful but had clearly received totally inadequate training for the job. He had no idea what SSH was or what logging through to a remote machine was.)

[pippincp]

Why don't you connect the D-Link to serve the older laptop?

[aaronsloman]

pippicp wrote "Why don't you connect the D-Link to serve the older laptop?"

Interesting idea. There are three options you might have had in mind:

(a) disable wireless on superhub and connect the dlink (DIR-615) to it as wireless router.

(b) connect the dink to the superhub and have two wireless routers.

(c) connect the dlink to the laptop via its ethernet port and turn off the laptop's own wireless

card (I suspect it cannot function in this mode, though some other dlink models can switch between being an access point and being a receiver).

Option (a) requires the dlink to have an 'auto' mode that can handle both 802.11n and 802.11g at the same time, with no impact on the 11n speed. I think it has such a mode, though I never tried it, because when it was installed I had only the old laptop with 11g wireless card.

Option (b) requires two wireless access points sited close to each other. I don't know if that would cause problems.

I may investigate option (a) later, but for now I like having one less power socket in use, and one less device on the equipment shelf!

If/when I try this I'll report whether it works. I think switching the superhub into behaving like a simple cable modem without the router functions is possible but messy.

Thanks

[phuego]

Aaron, thank you very much for posting this information - my remote SSH times out the moment I turn my back since change to Superhub.  You're a frustration saver sir.

best

Adrian