Making telnet think there is a connection

STaN

Hi,

we have 2 sites linked via ISDN.

On site 1, workstations access our server via Windows DW to gain access to our (ancient) accounts package.

Now with out previous routers even if the ISDN link was not there, and some1 went to use the system, the router would dial up, connect and you could continue working as normal.

Now, after installing a new router at one end, the connection times out after an idle of 6mins but when some1 goes to continue working, Windows DW says connection to host was lost and asks to RETRY or CANCEL. This causes a nuisance as the software has to be reset each time this happens as that user had not been logged out and so 2 user sessions are seen to have been created.

Any ideas why changing routers would change the behaviour of this or how it could be rectified.

Any help is appretiated.

Stephen

Are the routers not dialing out on demand, or is there a delay or something before they do so?

ssh

Assuming there is NAT going on there, the problem is probably related to the NAT table being flushed when the line goes down.

I've used dial on demand routers (actually a linux machine with an isdn card) with NAT that would quite happily pickup interactive sessions after bringing up the line again.

There's the technical low down on your problem (probably). I don't know what setting you need to change on your router.

STaN

sounds like it might be the NAT then.

What would that option normally be under?

would static routes or anything similar be an option to solve?

ssh

Nah, routing is an OSI model layer 3 issue, you're sort of worrying about layer 3 and a half here

It's the same model router as the old one?

Really, it's pretty unusual for something to flush the NAT table when the interface goes down, but you're probably looking at some option near the "disconnect after X period of time" option, I'm guessing.

What model router is it?

STaN

the old router was a perle 840

the new one is a Dlink Di-304

ssh

And you have the firmware up to date? Can always be a huge factor.

niallb

Possibly the router is using DHCP to assign IP addresses to incoming calls.
What you're seeing will happen if the new connection is
from a different IP address.

Try setting the router to always give the same address to the line.
I think you'll find that that was the old behaviour.

Worth checking anyway,
Good luck,
NiallB