VPN Connection High Overhead Traffic to NT Server

[jcwebb]

I have a VPN Connection established and working between my home laptop using Windows 2000 and IPSec through a NAT Router (Netgear RP114) and Cable Modem to the office LAN running Windows 2000 Small Business Server via a LinkSys BEFVP-41 VPN router. I can log onto to the remote server fine, browse the network, etc.

My issue is that there appears to be a high amount of traffic over the secure link (as monitored by 'ipsecmon'). Something on the order of 10-20 MB per hour, even when the connection is completely idle; i.e. I have one remote drive 'mapped' but am transferring no files, no applications running which access files on the remote network, and none of the files which I have enabled for 'offline access' are being used on either end so no synchronization is taking place.
This seems like a very high amount of traffic just to keep a connection established and a drive mapped. Anyone know what could be the reason for this volume of traffic or what additional tools I can use to narrow down the reason for it?

Thanks
John Webb

 

[markku]

Try disabling all unnecessary functions in "advanced" page of BEFVP41, like keep-alive and NetBIOS-broadcasts.

 

[jcwebb]

Thanks for the suggesstion, I checked and both those options were already cleared for my Tunnel. Only checked item is 'anti-replay' which the linksys manual indicates is a security feature to ensure security at the IP packet level.
I have my key lifetime set up at 3600 sec., so it is only supposed to renew every hour; however, looking at the VPN log on the router is shows "Set up ESP tunnel with nnn.nnn.nnn.nnn Success! every 6 minutes, instead of every 60. Maybe this is the issue? I'll try increasing my key lifetime from 3600 sec. to 36000 sec. just to see if it makes a difference.