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ADSL and Nortel Contivity

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ADSL and Nortel Contivity

My normal ADSL connection works great for home use, but logging into work where they have a Nortel Contivity server, that provides secure access to the corporate intranet, I always lose the connection within 5 - 10 minutes. What Contivity does is to re-make the connection back from Plusnet to me so that it is secure. What it will not support is any change to the routing tables once the secure connection has been made. Invariably when the conneciton fails, I get the message 'Cannot change the routing table once connection established - connection closed'.

Has anyone come across this? Is it to do with how PlusNet manages ADSL connections? I'm using a Zoom USB modem, which seems to work perfectly when I'm not dialled up to work.

I have a friend who works for Nortel, he's dug me out a bug sheet from Contivty and I've gone through every parameter setting checking that it doesn't apply to me. I've added it below for reference.

Solution 1
Solution ID: NORT30884
Product Family: Enterprise Data Create Date: 10/10/2001
Title:
How to correct Extranet Client error message: "The routing table cannot be altered after the Extranet connection has been established".

Facts: Enterprise Data Contivity Extranet Access Client Windows 2000

Symptoms: How to correct Extranet Client error message: "The routing table cannot be altered after the Extranet connection has been established" on a Windows 2000 machine.

Fix:
Windows 2000 supports dynamic changes to the routing table. The 2.62.47 Extranet Client does not support this because of security issues.
The error message can be caused by either:
1) A DHCP server reassigning an IP address for the PC or router.
2) The Windows 2000 client being part of a Dynamic DNS update, which changes the routing table on the PC.
Increase the DHCP lease time, or disable Dynamic DNS to alleviate the problem.

Disabling Dynamic DNS:-
To do this once Windows 2000 has been installed, open the Network control panel, bring up the Properties box for the Local Area Connection, open the Properties for TCP/IP then go to Advanced/DNS and turn off the option "Register this connection's addresses in DNS". You can also do this during a custom install by going into the Properties of TCP/IP at the appropriate point in the installation process.

Solution 2
Solution ID: NORT133209 Product Family: Enterprise Data Create Date: 05/31/2003
Title:
Error: "The routing table cannot be altered after the Extranet connection has been established"
Facts: EAC Extranet access client PC window
Symptoms: Error: "The routing table cannot be altered after the Extranet connection has been established" Connection drops every 15 minutes.
Fix:
Disable the Rip Listener on the Client PC.

1. In Start/Settings/Control Panel, double-click Add or Remove Programs.
2. Select Add/Remove Windows Components.
3. In the Windows Components Wizard, click Networking Services.
4. Click Details.
5. Select the Rip Listener. Check to disable if needed.
6. Click OK.

If this doesn't apply then:

1. On the PC in the dos prompt type "route print". This will give the PC's route table. Leave it open, but minimize it.
2. Connect to the vpn until the route table message appears.
3. Open another dos prompt and type "route print" again.
4. Compare the two route tables to look for a change in the route table.

Perhaps there is a change in an IP address. What device is assigned this address, and what DHCP Server is assigning it?

1. Give the device a static or permanent IP address.
2. Increase the lease time for the device to longer than 15 minutes.
1 REPLY
Community Veteran
Posts: 14,469
Registered: 30-07-2007

ADSL and Nortel Contivity

I suggest you contact Nortel Support as it is the software that is at fault, not your connection or what PlusNet do. I had exactly the same issues when working for Nortel and another ISP and never did find a solution. It would fail anytime between a few minutes and a few hours with no pattern and it was very annoying. I was also using a router so there would not be any routing changes on the PC so I don't think the error message seen actually relates to the problem that caused the disconnect.

The fact that it set up a VPN suggests it is something on Nortels network that is causing the issue not on your PC or with PlusNet.