Some time ago we encountered a frustrating issue with a Watchguard MUVPN client dropping connection every 2 minutes 
This happened connecting long distance to Hong Kong where latency definitely cause extra difficulties.
I got the solution handed out by my overseas friend.
Solution :
The reason was that the keep-alive settings protocol was blocked by the Windows client firewall.
Name: IKE Keep-Alive Messages-1
Port: 4500
Port: UDP
Environment: From your VPN-Gateway
Name: IKE Keep-Alive Messages-2
Port: 500
Port: UDP
Environment: From your VPN-Gateway
You can use the Netsh command for this as well.
Open the CMD as Admin and run these 2 commands.
netsh advfirewall firewall add rule dir=in name=”IKE Keep-Alive Messages-1″ Profile=Domain,Private protocol=UDP localport=4500 action=allow
netsh advfirewall firewall add rule dir=in name=”IKE Keep-Alive Messages-2″ Profile=Domain,Private protocol=UDP localport=500 action=allow
Create 2 firewall Inbound Exception Rules and there you go ! 
Posted by audministrator 
