Using telnet from home pc to OVMS system in office

[Diane M. Morin]

Hi,

I'm trying to set up my home pc so I can telnet into my OVMS system here at work. I'm able to use putty from my office pc and create multiple sessions. However, when I vpn in from home and try using putty, I'm lucky if I can get one session to work.

TCPIP Services for OpenVMS Alpha V5.4 ECO 4
OpenVMS v7.3-2
DS20 500MHZ

Any ideas?
Diane

[Steven Schweda]

How does "work" differ from 'not "work"'?

[Diane M. Morin]

Here at work I'm on the corp. lan. At home I'm using an ISP and then must use vpn to access internal sites. I'm able to access other nodes on the corp lan. It's just this one.

diane

[Steven Schweda]

That seems to be the answer to:
How does "office" differ from 'not "office"'?

My question is more like what did you do, and
then what happened? In what sense or manner
does it not work from home? Error messages?
Sloth? Disconnects? What?

[Diane M. Morin]

From home:

I connect using putty to the OVMS server and I get network connection timeout. That's the only error I see. I'll keep trying and once in a while I do get connected.

In the office:

I can get connected every time.

[Andy Bustamante]

We need a bit more information. Are you using a private or public address to connect to the VMS system? What VPN software are you using? Does it force all traffic through a VPN tunnel or selected traffic? Does the VPN place you into a different subnet than your desktop?

On the VMS side, are there any traffic restrictions (TCPIP SHOW SERVICE TELNET/FULL and look for reject/accept entries)?

Since this works from your desk, it's probably a network configuration issue that needs to be identified.

Andy

[Robert Gezelter]

Diane,

If you are getting a timeout, I would suspect that there is a filter on the VPN gateway (or near it) that is blocking that port.

Check if you are using telnet or ssh (among other ways of getting a terminal session). Determine what port number is being used to establish the session. Then check with your network staff as to whether traffic is allowed on that port. You will save a lot of time.

If you can put an analyzer on the segment that the OpenVMS system is on, you can also see if the session initiation dialogue is ever reaching your system. I rather suspect that it is not.

- Bob Gezelter, http://www.rlgsc.com

[Art Wiens]

Can you actually "see" the VMS system? ie. ping and/or traceroute to it compared with a ping or traceroute to a system that "works" from your vpn connection.

Cheers,
Art

[Steven Schweda]

I also would try some other service, say, FTP,
to see if everything is hosed or just some
things. Blame the VPN first, I always say.

[Ian Miller.]

I do this using putty and ssh. I had to enable sending of null packets to keep the session alive (putty connection settings) as something (firewall parhaps) used to timeout my connection if I paused for thought.

You should be using the current version of putty 0.58

[Diane M. Morin]

I found some more anomalys that I am tracking down. It appears right now that I have the same problem when I'm not on the same subnet. I also found another system, which is running Tru64, having the same problem. The 2 systems can talk to each other and my pc w/out a problem.

Stay tuned and I'll let you know what I find out once I talk with the network folks.

[Diane M. Morin]

I think I figured out the problem. It appears to be a faulty network card on the system. I enabled the second network card and am able to telnet to the system from anywhere.


Thanks for your help
diane

[Terrence Branscombe]

Diane,

Like you I often connect to an OVMS server at work using PuTTY and SSH. I too had connection reliability problems but found that some PuTTY session settings needed to be tweaked. Enabling TCP keepalives and increasing the "Seconds between keepalives" in the PuTTY session's "Connection" setup eliminated the problem.

Cheers,
Terry

[John Gillings]

Diane,

If you have a flaky connection, you may want to think about enabling virtual terminals so you can reconnect to a disconnected session.

A 1+: if you have several systems to connect to in the local LAN, consider choosing one as your "primary", and set a long TTY_TIMEOUT. Connect to it first, then to the other systems. If you lose your VPN, your PC crashes or you get a power failure, you can charge the paste buffer with username and password then reconnect all sessions quickly and easily, since they'll all have the same initial username/password.

[Diane M. Morin]

Thank you for information above. I'll look into implementing them.

diane