What is a VPN passthrough?

You may have come upon it when searching for a VPN on the internet. Nonetheless, you have no idea what it is or what it has to do with anything. Don't worry; you've found an article that will tell you all you need to know about it.

A VPN passthrough is a router functionality that enables outbound VPN connections from devices connected to the router. It permits the free flow of VPN traffic. It should not be confused with a VPN router, which establishes a VPN connection.

How does the passthrough function?

NAT is a feature that almost every router has. Some routers may allow up to three VPN connections at once, making them ideal for use in a small office or at home. PPTP and IPsec VPNs are incompatible with NAT, as we've already said. The element of PPTP that prevents NAT is called GRE (Generic Routing Encapsulation). GRE is replaced by an updated GRE that is NAT compliant through VPN passthrough.

The TCP channel is used by PPTP, which uses port 1723. The GRE protocol aids PPTP in encapsulating information and establishing the VPN tunnel, while this channel facilitates control. Remember that the problem is with the GRE, which does not support ports, not with PPTP.NAT doesn't operate with GRE since it requires a connection with a port number and an IP address, which GRE doesn't have. This is where PPTP passthrough comes in.

Difference between VPN router and VPN passthrough?

These two are not even close to being the same thing. VPN passthrough is the router's software functionality to enable VPN traffic to pass through. It doesn't do any VPN operations on its own.

A VPN router is a router on which a VPN client has been installed. It is not supported by all routers, but it is by most. Would you want to learn more about it and potentially set one up in your own home? Read more about VPN routers in our post. Created with

How to set up a router such that VPN passthrough is enabled

  • To begin, open your favorite browser and connect to a local network.

  • Enter the IP address supplied by your router's administrative application into the URL bar.

  • Enter your admin ID and password.

  • Select the option to enable PPTP passthrough in the security setup settings.

  • Activate PPTP on port 1723 in the port forwarding options.

  • Return to the Windows key and enter VPN in the search field.

  • Go to the settings and make your selection. Establish a VPN connection

  • In the Internet Address area, type the VPN's IP address.

  • In the Destination Name area, type the VPN's name.

  • Create a VPN by checking the box that says, "Remember my credentials."

  • Select VPN and Connect from the Networks box.

  • Consider the job done once you've entered the login and password.

Why is it necessary to use passthroughs?

There are two sorts of routers: those that support VPN connections natively and those that do not. IPsec (Internet Protocol Security), PPTP (Point-to-Point Tunneling Protocol), or L2TP (Local Area Tunneling Protocol) are all options for routers that accept VPN connections natively (Layer Two Tunneling Protocol).

Some routers aren't built to operate as VPN servers. VPN communication is prohibited since they do not support this technology natively. You must work around this restriction in order to install a VPN. This is feasible thanks to the VPN passthrough feature. When enabled, traffic from VPN client is sent to the VPN gateway over the internet. Since they support both PPTP and IPsec VPNs, many home routers allow VPN passthrough, and those that do are widely regarded as the norm. In other words, devices in a private network will be able to establish outbound VPN connections with this functionality. It has no effect on inbound VPN connections or interferes with their regular operation in any way.

Its name is born from the fact that VPN traffic can be routed through the router. This does not necessitate the opening of any ports. The entire process is computerized.

How can you know whether VPN passthrough is active?

Start by verifying whether your router has options for IPsec or PPTP passthrough if you're not sure you've activated the passthrough capability. Then navigate to the Security tab on your router's portal. Select the VPN passthrough sub-tab from the drop- down menu. Check that the IPsec (50, 21/ 500), L2TP (1701), and PPTP (1723) ports are all open. If you still can't connect to a VPN, talk to your VPN provider about the software setup.

Only a router with the PPTP or IPSec passthrough function may establish an outbound VPN connection. You can ensure that the functionality is operating on your network by following the step-by-step tutorial provided above. The VPN ensures that your private information stays anonymous and difficult to intercept by encrypting the data travelling between your device and your network. No one can see what you're doing online if you do it this way.

Is it possible to disable VPN passthrough?

VPN passthrough is used by small office and residential network gateway devices as a passive device that enables VPN data packets to pass through a firewall rather than as a VPN termination point. Depending on the kind of VPN, several protocols are required to infiltrate VPN traffic. User Datagram Protocol (UDP) on port 500 for IKE and port 4500 for NAT traversal is required for IPsec. In the setup menu, you may turn off this option.

What are the benefits and drawbacks of turning off VPN passthrough?

VPN Passthrough is disabled, which improves your online security by blocking open communication ports on the firewall, which would otherwise be available and open to anybody. On the down side, a VPN connection is not feasible since the relevant ports are blocked by the NAT firewall. If your workplace or home network relies heavily on VPN, these ports must always be available.

If you don't require a VPN, though, you may turn off your router's passthrough capability. All protocols and ports are banned by default, however, you may always open them if necessary. You can prevent L2P2, IPSec, and PPTP protocols from going through your router's firewall by deactivating VPN passthrough. Simply go to the settings and choose "disable" before saving your changes.