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Slow ICS after adding Cisco VPN

I have a broadband connection going directly into a NIC on my Win 2000 PC. I am running BlackIce v. 3.6 as a firewall on this PC. I also run MS ICS on this host PC, and connect to my 3 other home PCs through a second NIC (all IP addresses in the 192.168.0.X range). The other 3 pcs on my home network all run Win98SE, and connect to the Win 2000 PC through an old Black Box hub, with two upstairs PCs also connecting through another hub (Linksys NH1005). This setup has worked great for several years, with little discernable difference in speed between the Host and clients.

I recently added Cisco Systems VPN client v. 3.5 to the ICS host. This VPN connection is not run often, but when we do run it, it works great. I understand that ICS will not work while the VPN connection is active. The problem is that ever since I installed the VPN, when the VPN is not running, the ICS connections to the other 3 PCs run VERY SLOWLY, causing many timeouts. I can still connect to some internet sites without any problem, but many sites just timeout.

I would appreciate any suggestions on what to look at/do to return the ICS client PCs to their previous browsing performance level.

When I ran this by the Microsoft network newsgroup, it was suggested that perhaps “My guess would be that the VPN Client added additional filters to the stack, and even through it isn't in use it is still parsing the traffic (for all intents and purposes).

I would appreciate any other suggestions you have to fix the problem.


New Member

Re: Slow ICS after adding Cisco VPN

I would suggest you to check the settings of your ICS host and make sure it is not blocking IPSEC traffic. Like UDP 500, Protocol number 50 and 51 for ESP and AH respectively.

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