So you’ve recently bought and installed one of those VPNs people keep talking about. You’re not quite sure how it works, but it’s doing its job and you couldn’t be happier. That is, until it doesn’t. Your VPN isn’t connecting to a particular public Wi-Fi network and you’re starting to feel like you wasted money on a scam. For starters, you didn’t waste money. The VPN is working as intended, but it’s actually the network that’s giving you issues.

You see, VPNs have protocols, specific security features that each protocol provides while you’re surfing the web. These protocols use networking ports, giving VPNs their ability to pass traffic in and out of your VPN client or your server device.

Long story made short, you’re port is being blocked. The network you’re attempting to connect to with your VPNs specific port isn’t accepted by the network.

What a VPN is and Why you Should Use One

VPNs are all about security and privacy, it’s in the name; a virtual private network adds a level of security and privacy to your network that you wouldn’t get connecting otherwise. And it can be especially helpful when you’re connecting to public Wi-Fi networks all over town. It’s a lot like handling dirty dishes with a pair of rubber gloves; the rubber gloves is your VPN.

First off, a VPN is going to hide your IP address. Anyone, or any network, viewing your IP address isn’t going to see anything. Or, if you prefer, a VPN can change your IP address to something different, like hiding your true place of origin and making it seem like you live in another location. On top of that, they encrypt your data so any transfers made on your network, or any public network, will be protected from any snooping.

The wonderful benefit of using a VPN certainly protects you–that’s its job. However, thanks to its uncanny ability to mask your location and provide networks with a different place of origin, you can use this to your advantage by gaining access to content that’s banned, blocked or unavailable in your area.

Your VPN Might Be Blocked

The security and privacy VPNs provide is dependant on its protocol. Certain protocols are better than others. These protocols then branch out into different ports, and ports give the information a road to drive on.

The biggest reason your VPN isn’t playing nice with the public Wi-Fi is most likely due to it not accepting your VPN’s port.

You typically don’t witness businesses setting up their on restrictions. This is usually done by the network providers themselves that want your data. One of the core reasons VPNs are so popular is because any data that’s collected while you use a network connection, like websites you visit and what you do, is then shipped off and sold. Those would-be buyers wouldn’t profit very much off of encrypted data. Therefore, certain ports can be restricted access. That’s a bummer. So, what kind of protocols and ports are there?

Popular Protocols in Circulation

Not all protocols are created equally. This goes for network connections as well. That being said, which one is the best? Well, it depends. Below you’ll find common VPNs and what they offer.

PPTP: This is by far the weakest, and nearly useless, VPN protocol. PPTP is akin to “Wired Equivalent Privacy,” (WEP). It’s old, offers very little to no encryption at all, and has next to no use except maybe for streaming a video or two. Don’t bother with PPTP. In fact, if your VPN only offers PPTP, you run the other way. Don’t use PPTP unless it’s absolutely necessary, like a dire situation. Even then, you’d probably have more luck sending your data via smoke signals. PPTP

OpenVPN: Certainly the most popular of the VPN protocols. OpenVPN is your go-to, if it’s available, above all other protocols. OpenVPN is incredibly difficult to decrypt and incredibly difficult to block. This is because OpenVPN is often mistaken for HTTPS and SSL traffic. What makes OpenVPN special is its ability to play nice with any port. Most VPN providers will use this as their flagship.

The downside to OpenVPN is it doesn’t come integrated in any systems. Instead, you utilize OpenVPN through third-party software. Its other downside is, because of its heightened security, your connection may experience a dip. It’s the price for so many checks and balances.

L2TP/IPSec: L2TP/IPSec is a hybrid of sorts as well as an extension of PPTP. L2TP by itself doesn’t bring an encryption to the table. Instead, PPTP is filtered through L2TP and then encrypted by IPSec, a protocol that’s already established a healthy popularity for its high security measures.

SSTP: Even though Microsoft developed SSTP and stuffed it into Windows Vista, that still wasn’t enough to convince users to use Windows Vista. Better than L2TP and can sometimes go toe-to-toe with OpenVPN, SSTP uses AES encryption. If you’re willing to trust Microsoft, then using SSTP isn’t out of your reach. It does have a knack for bypassing firewalls.

IKEv2: Another protocol Microsoft helped developed–not alone–but alongside Cisco. However, calling it a “protocol” isn’t entirely accurate, but it might as well be. You’ll find IKEv2 in mobile devices that use 3G and 4G LTE. IKEv2 plays nicely with AES and IPSec encryption.

Like SSTP, if you’re a fan of Microsoft and have no problem trusting them, you’re welcome to use it. You can find versions that don’t have Microsoft’s hand in.

The bottom line is this: if you can’t connect to a public Wi-Fi with your VPN, then you’ll have to consider using a different port. Each protocol works with certain ports and it may feel like a game of cat and mouse. It’s not the VPN’s fault, it’s the network. VPNs are still worth investing in.