This one has me really stumped. I have a client that want to VPN to her office from home PC, now the setup is bog standard.
OFFICE: SBS 2003 RRAS configured through wizard, have no probs connecting from any device anywhere ( almost )
HOME: linksys router, ( this one, brand new, also her third one ) PC DELL precision t3500.
Now, this has worked in the past, and tends to every now and then, but the VPN fails at username & password, end up with the usual 806 error and the server tells me that there was router / GRE issue. The wiered part is that this PC can connect to my server, other VPN servers I've set up, just about anywhere. Nope, its not the router as she also has two other laptops at home, they can connect just fine.
Have replaced routers, NIC'S and the PC ( for other reasons ) has had powersupply, motherboard, hardrive & nICS again, it's in a new state, just been re-installed from scratch. It just doesnt make sense.