For a telecommuter or remote worker, a poor or no connection to the office can be as serious of a problem as not having an Internet connection. If you’re such an employee and are experiencing problems with your VPN connection, this article lists some of the things you can do on your end before your IT team needs to intervene.

Complete remote worker's guide for VPN troubleshooting

In any case, the vast majority of issues with a VPN connection are usually on the client side and not on the corporate network, even though that too can happen. However, as you try these fixes, make sure you attempt only the ones you’re confident in and if you think it’s a serious problem, contact your company’s IT team.

Have a look at the setting of the VPN

In most cases, your company’s IT department will have provided you with a VPN client software to install, instructions on how to install it, and your login credentials for accessing the network. Confirm that the configuration setting that you entered are exactly the ones that the IT team specified in the instructions. Just in case, re-enter the log details.

Confirm that your Internet connection is working

Launch your browser and try and open different websites to confirm whether or not your Internet connection is actually working. In case you’re on a wireless network and you’re experiencing problems with the signal strength or the Internet connection, you may need to first troubleshoot the problems on the wireless connection before troubleshooting your VPN.

If you’re using a browser-based VPN, check the browser

To begin with, make sure that the browser you’re using is the correct one and that it’s up to date. Some remote access solutions and SSL VPNs can only be used over a browser, as opposed to installing a client software. However, many of these VPNs work only with specified browsers—Internet Explorer, in most cases.

Therefore, make sure the browser you’re using is supported by your company-provided VPN, confirm that you’re using an up-to-date version of the browser, and keep an eye out for any browser notifications (such as Active X controls) that you may need to look into before you launch the VPN connection.

Confirm that the problem is not with your home network

If you work on a laptop, connect to the VPN through a Wi-Fi hotspot and see if it works from there. If it’s functioning as required on the Wi-Fi network, there’s a chance that your home Internet connection might have some issues. The troubleshooting tips that follow are useful if you experience home network issues that may lead to problems with your VPN.

Check whether the IP subnet of your home network and company network are identical

VPNs cannot connect in cases where a remote computer seems to be making a local connection to the company’s remote office. In other words, if your home device’s IP address is in the same cluster of IP addresses (IP subnet) used by your company’s network. For example, if your company’s network uses the addressing scheme 192.168.1.[1-255] and your home computer also uses 192.168.1.[1-255].

If you don’t have the details of your company’s IP subnet, contact your IT team and have them provide it. If you’re using Windows, you can determine your computer IP address by going to “Start” then “Run”. Type in “cmd” to launch the command prompt window, type in “ipconfig/all” and tap Enter. Check the “IP Address” in your network adapter.

If you find that your company’s IP subnet is the same as your home network IP subnet, you can fix the problem by making some changes to the settings of your home router. Go to the configuration page for your router (for the administration URL, check the manual) and change the IP address of the router to one in which the first three blocks of the number in the IP address are not the same as the ones in your company’s IP subnet.

For example, in the IP subnet example we provided earlier, change it to 192.168.2.1. In addition to that, go to the DHCP Server Setting and change it so that the range of IP addresses given out by the router is 192.168.2.2 to 192.168.2.255.

Confirm whether VPN is supported by your home router

VPN passthrough, a router feature that lets traffic go through the Internet freely, is unsupported by some routers. Other routers may not support the protocols used by your company’s VPN. Whenever you buy a new router, always check to see whether it supports VPN and which protocols it supports.

If problems occur as you attempt to connect to your company’s VPN using your current router, search online for the specific brand model and include the word “VPN” in the search to see if there have been reports of it having issues with certain VPNs and whether any fixes are available. In some cases, the manufacturer of the router may offer a firmware upgrade that introduces VPN capability. However, before buying a new router, contact your company’s IT department.

Enable VPN protocols, ports and passthrough

Check for the following options on the personal firewall configuration settings and router settings on your home network:

  • Port Forwarding & Protocols. Both your router firewall and other firewall programs might require specific protocols opened and ports forwarded. Microsoft’s VPN tunneling protocol PPTP requires you to enable IP protocol 47 (GRE) and to forward TCP port 1723. For IPSec VPNs, you need to open protocols 50 (ESP) and 51 (AH) and forward UDP port 500 (IKE).
  • VPN Passthrough. In most cases, if you check the security settings, you’ll find an option for enabling PPTP or IPSec Passthrough. (These are the two most common VPN varieties.) If your IT department hasn’t told you which variety of VPN you’re using, enable both. Just bear in mind that not all routers come with this setting and missing it doesn’t necessarily mean your VPN won’t work. Having it is reassuring, though, because it is an indication that you have a VPN-friendly router.

If all this sounds too technical, don’t worry. Start by checking your router’s website documentation or manual for any mention of “VPN” and all the instructions (along with illustrations) should be there.

Reach out to your company’s IT department

If none of these troubleshooting fixes work, call your IT guys and let them know which of them you tried, the type of resources you’re using (operating system, Internet connection, router, etc.), and the error messages you came across.