IMPORTANT NOTICE: IPv6 Rollout on BolehVPN and IPv4 only servers

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IMPORTANT NOTICE: IPv6 Rollout on BolehVPN and IPv4 only servers

What is IPv4 and IPv6?

IPv4 and IPv6 are two ways to express IP addresses.

An IPv4 address is expressed in 4 sets of numbers separated by dots that look something like this:

IPv4 has been used since 1983 and offers a maximum of 4,294,967,296 addresses. The majority of internet traffic is still routed through IPv4 addresses. Amazingly, these addresses are running out and this problem is commonly referred to as IPv4 address exhaustion.

This is where IPv6 comes in. IPv6 is the successor to IPv4 and supports a whopping 340,282,366,920,938,000,000,000,000,000,000,000,000 addresses which should be sufficient for a very very long time to come. IPv6 addresses look different and are represented by 8 groups of four hexadecimal digits:


However the take-up rate of IPv6 is still slow. According to Google, only about 13% of its users access them via IPv6 though this is quickly picking up and we expect it to continue to do so over the next few years.

IPv6 Adoption

Image courtesy of Google

Why is this Relevant to Me?

First of all this only affects Routed and SurfingStreaming servers (this includes Cloak routed and Cloak surfing streaming). Proxied and BolehGEO configurations are not affected and remain on IPv4. Explanation will be below.

During the transition period where both IPv4 and IPv6 addresses are in use, there are now two sets of IP addresses to hide: one your IPv4 address and one your IPv6 address.

If both IPv4 and IPv6 is enabled on your end, if a VPN only supports IPv4, then your true IPv6 addresses will leak destroying your anonymity! This is often referred to as IPv6 address leak and was identified as a problem with privacy VPNs way back in 2015. We had then recommended that users disable IPv6 in their network adapters to be safe so that IPv6 cannot leak. The problem wasn’t as severe then with IPv6 adoption at only about 6% and it was also very hard to solve as OpenVPN’s IPv6 support was often still buggy. Furthermore, there are those who consider IPv6 addresses potentially less private than IPv4.

However with the increase of IPv6 use it now becomes imperative for us to protect users on both ends and relying on users to disable IPv6 is no longer practical. As such by default we are enabling dual stack IPv4 and IPv6 across all our Fully-Routed and Surfing-Streaming servers which means that you will be protected by our VPN whether you are on IPv4 or IPv6.

Proxied configurations remain on IPv4 as the proxy is specified directly into the program and its up to the program to properly use that. It should be safe for IPv6 users to use as long as the program’s proxy support doesn’t leak. We don’t recommend proxied configurations for the privacy conscious though. BolehGeo also remains on IPv4. Services such as Netflix also block IPv6!!

What if I don’t want to or can’t use IPv6? Oh no! MORE CONFIGURATIONS!

There are still devices such as older routers that don’t support IPv6 or users that disable IPv6 for privacy or other reasons. Unfortunately this makes it incompatible with the dual-stack setup and you may experience an error like the following:

Fri Feb 03 19:20:21 2017 NETSH: C:\Windows\system32\netsh.exe interface ipv6 set address interface=27 2001:df1:800:10e:11:0:2:1051 store=active

Fri Feb 03 19:20:21 2017 ERROR: netsh command failed: returned error code 1

If you disabled IPv6 previously and don’t mind turning IPv6 in your adapter, just turn it on by following this knowledge base article.

However if you do not wish to do so or your device doesn’t support IPv6, we have our IPv4 only VPN servers and they can be identified by their prefix of IPv4 on the OVPN configuration or on the dropdown selection. All other Fully Routed servers not marked, will have dual stack support (IPv4 and IPv6 support).

IPv4 prefixed configurations only protect your IPv4 address. Only use it if you know what you’re doing!

Currently we have rolled out IPv6 to all servers except Japan, Italy and Luxembourg which we are awaiting IPv6 allocation and will complete this in the next few days and announce it here.


Remember, if you use IPv4 only servers but you have IPv6 support, your IPv6 address will leak and may expose you!

Key Takeaways

For most users, all you will notice is that there are now more configurations to scroll through and we apologize for this. We’ll see how we can reorganize the GUI better.

We recommend for you to use our regular configurations which supports both IPv4 and IPv6 and protects you in both addresses. In other words do not use IPv4 only servers unless you know what you are doing or require it!

Our IPv4 only servers are there for those who need it. We thank you for your understanding and your continued support of BolehVPN!


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