Hi, I've just inherited a Cisco VPN Concentrator & below is the version: Bootcode Rev: Cisco Systems, Inc./VPN 3000 Concentrator Series Version 2.5.Rel Jun 21 2000 18:57:52 Software Rev: Cisco Systems, Inc./VPN 3000 Concentrator Version 3.5.2.Rel Feb 14 2002 12:10:21 Recently we just setup a virtual office at McLean, Virginia, US. Our admin there has successfully setup a Linksys wireless router so everyone can surf internet. The Linksys is plugged to the only RJ45 socket on the wall. However, only 1 user at a time can VPN (they use Cisco VPN Client v.3.6.3 and 4.6) to our office here in Singapore. I've looked at: Cisco Document ID: 5753 ([URL="http://www.cisco.com/en/US/products/hw/vpndevc/ps2284/products_tech_note09186a00800946af.shtml"]www.cisco.com/en/US/products/hw/vpndevc/ps2284/products_tech_note09186a00800946af.shtml[/URL]) - I can't find 'IPSec through NAT' under Configuration->User Management->Groups, then Modiy Group, then IPSec tab. I did find IPSec over UDP and IPSec over UDP Port under 'Mode Config' instead of IPSec tab. Are they the same? - I also can't find 'NAT Transparency' under Configuration->System->Tunneling Protocols->IPSec. I enabled IPSec over UDP & IPSec over UDP Port (use port 10000), and on the client tick on "Enabled Transparent Tunneling" + IPSec over UDP. Yet, still only 1 user can connect at a time. Anything I missed? THANK YOU in advance. regards, Sur