Image Added Step 4: Check if you require an IPSec pass-through, or whether this has been set up already. By default an IPSec connection uses the port 500 UDP, the IP protocol ESP (50), or port 4500 UDP. The VPN tunnel may occasionally be directed via routers which do not support IPSec pass-through. In these cases, the IPSec packets may be handled incorrectly, or they may even be dropped. A result of this is that, even though the tunnel has been established, it cannot be used for communications. This problem can be avoided by activating port forwarding for the UDP ports 500 and 4500 on the client-side of the router. For a description on how to set up port forwarding on a LANCOM router, see this Knowledge Base article. Step 5: If you cannot use IPSec pass-through, you have the option of setting up a VPN connection based on IPSec over HTTPS. All you have to do in this case is to open the HTTPS port 443. With IPSec over HTTPS, an attempt is first made to transfer data using standard IPSec. If the connection cannot be established (e.g. because IKE port 500 is blocked), then an attempt is then automatically made to establish a connection that encapsulates the IPSec VPN in an additional SSL header (port 443, like HTTPS). For a guide on setting up a VPN with IPSec over HTTPS, see this Knowledge Base document. Step 6: If you are using a computer or a notebook from HP (Hewlett Packard), where the HP Velocity software is installed, deinstalling HP Velocity fixes the issue. Step 7: The VPN tunnel does not work using a UMTS/3G or LTE/4G connection. The following reasons may be causing the problem where a LANCOM Advanced VPN Client is operating on a computer which uses 3G/4G for its Internet connection. 7.1) The 3G/4G provider blocks communications on ports 500 and 4500, or the provider blocks the ESP protocol. In this case, contact the provider of your connection. 7.2) There is a conflict between the LANCOM Advanced VPN Client and the 3G/4G management software. If this is the case, you should prevent the 3G/4G management software from starting with the operating system, and you should allow the 3G/4G connection to be established by the LANCOM Advanced VPN Client. For a description of how to set up a VPN client connection via 3G or 4G, see this Knowledge Base article. Step 8: If your workstation has more than one active network adapter, please check the default gateway. Having more than one default gateway on a workstation may cause the packets to be sent in the wrong direction, or not to be sent at all. 8.1) You can read out your network settings by entering the command ipconfig at the Windows command-line prompt. To run this, click on Start, Run... and enter the command cmd. |