We are using site-site Tunnel formed between PIX firewall at one remote location to Cisco VPN concentrator connected

at central side. On the central side their are number of subnets that all been added to the network list on both PIX & VPN concentrator to enable remote site to access all the subnets on the central site. Problem is that while Tunnel is running it suddenly drops all packets for one particular subet on the central site. I have tried all possible means of troubleshooting & but nothing seems to work. Pls help me out with any ideas if possible.