Question : Problem: VPNs Linksys QuickVPN and MTU questions

I did some reading on VPNs done by Microsoft and it says it lowers the MTU from 1500 to 1400. My question is if i'm using Linksys QuikVPN how do I lower the MTU or the real question is , does Linksys lower it for you on the client side?

Answer : Problem: VPNs Linksys QuickVPN and MTU questions

As rule, most VPN clients will auto adjust the MTU value based on the type of VPN connection. There is no need to make a change for the QuickVPN client.

Having said that, there can sometimes be issues with VPN's that require lowering the MTU value further to resolve. Common issues are dropped connections, especially when transferring large files, but too high an MTU can make it impossible to connect in some instances.
To lower the MTU value it is easiest if you use the common Dr TCP tool from  http://www.dslreports.com/drtcp  If possible it is also recommended to change the MTU value on the router ant the VPN client site as well.