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DSL/Nortel VPN/3Com Hub issue

We have been trouble shooting a VPN issue for several weeks and are quite perplexed! In a test enviroment, we have a branch office tunnel configured on a Nortel 1010. We have the public interface of the 1010 connected into a 3Com hub. We also have the ethernet port from our Westell modem plugged into the same hub. The Westell is configured with the network 192.168.0.0/24 and the ip of the Westell is 192.168.0.1. The public interface of the 1010 is configured with the ip 192.168.0.2, its subnet mask is 255.255.255.252 and its gateway is the Westell. We have the private interface of the 1010 plugged into a different hub and it is using a different ip network. The tunnel comes up, but we can ping the mgmt IP of the 1010 only intermittently. Sometimes we can ping it fine, sometimes it won't ping. However, if we leave a continues ping running, we discovered that we do get a successful ping every 240 pings, or every 4 minutes! We also discovered that if we plug the public interface of the 1010 directly into the Westell, that the pings work fine. Any ideas!?

Reply to
neicymath
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Thanks Mike. The problem with directly connecting the 1010 to the modem is that when it is shipped to a client's office, they may already have a device plugged directly into the modem and we do not want our device to replace theirs. Or they may have a hub or a switch plugged into it too which we cannot change. Also, we are not using a switch in our test environment - just two 3com SuperStack II PS Hub 40's. The Westell (using a Xover) and the public interface of the 1010 are plugged into Hub #1. The private interface of the 1010 is plugged into hub #2. I do believe that both interfaces are set to autonegotiate. Does that matter with a hub? I can set them to 10 and see what happens.

As for hardware, we're using some of the same cables, but not all, but we have used two different pairs of hubs plus two 1010's, so I don't think it is hardware.

Reply to
neicymath

If it works fine plugged directly into your modem then just do that. If you want to know the reason it fails with the switch, I would guess the port speed autodetection is failing, try setting the speed and duplex setting manually on both devices (VPN and modem). Also make sure that the public interface is not cross-wired to the private interface through that hub or you will have problems. (The public interface thinks the packets from the private interface are IP spoofing attempts)

It goes without saying that you tried a different switch and cables right?

Reply to
Mike Drechsler - SPAM PROTECTE

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