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D-Link FAQ => Router FAQ => FAQs => Topic started by: FurryNutz on March 26, 2014, 09:32:23 AM

Title: Basic VPN Troubleshooting and Suggestions.
Post by: FurryNutz on March 26, 2014, 09:32:23 AM
Most DIR series routers are VPN Pass-thru routers, meaning that very little if any VPN configuration is needed. However in some cases, more advanced settings are needed for a more active VPN connection configuration. These are suggested troubleshooting steps to help in VPN problems. It's recommended to contact your VPN provider or VPN IT department who works with your VPN for help and information regarding any VPN issues seen beyond this.

Internet Service Provider and Modem Configurations

Setup/Networking/Enable DNS Relay:
Setup/Internet/Manual:Use Unicasting: Off

UDP Endpoint Filtering:  Endpoint Independent or Address Restricted
TCP Endpoint Filtering:  Endpoint Independent or Port & Address Restricted
Enable anti-spoof checking:  UNCHECKED or Checked

NOTE: IPSec (VPN): Allows multiple VPN clients to connect to their corporate network using IPSec. Some VPN clients support traversal of IPSec through NAT. This Application Level Gateway (ALG) may interfere with the operation of such VPN clients. If you are having trouble connecting with your corporate network, try turning this ALG off. Please check with the system administrator of your corporate network whether your VPN client supports NAT traversal.

IPv4 Multicast Streams: Off

Advanced/Virtual Server Settings: May not be needed for most pass-thru VPN traffic.
IP47  47 0 → 0  Always  Allow All     
PPTP  Both 1723 → 1723  Always  Allow All     
L2TP  Both 1701 → 1701  Always  Allow All     
L2TP2  Both 450 → 4500  Always  Allow All 

3rd Party Security Software Configurations

Additional Resources:
DSLReports - Networking 101: The VPN (https://www.dslreports.com/shownews/Networking-101-The-VPN-137752)
http://forums.dlink.com/index.php?topic=13352.0 (http://forums.dlink.com/index.php?topic=13352.0)
http://forums.dlink.com/index.php?topic=56861.0 (http://forums.dlink.com/index.php?topic=56861.0)
http://forums.dlink.com/index.php?topic=10965.0 (http://forums.dlink.com/index.php?topic=10965.0)
http://forums.dlink.com/index.php?topic=13056.0 (http://forums.dlink.com/index.php?topic=13056.0)
http://www.orbit-computer-solutions.com/Types-of-VPN-Access.php (http://www.orbit-computer-solutions.com/Types-of-VPN-Access.php)
http://www.orbit-computer-solutions.com/Remote-access-VPNs.php (http://www.orbit-computer-solutions.com/Remote-access-VPNs.php)