IKEv2 Vs IKEv1

Lawrence Bonk Profile image

Written by:

Updated August 24, 2022

If you are new to the world of private networks, you may look to compare IKEv2 vs IKEv1. The best VPNs, after all, tend to rely on one of these two technologies. So what do IKEv1 and IKEv2 do in the first place, how do they assist VPNs, and how to choose between them? Keep reading to find out.


  • IKE stands for Internet Key Exchange, a protocol used to set up secure connections on a VPN.
  • IKEv2 is better than IKEv1 in nearly every way, as the former was created to answer some of the inadequacies of the latter.
  • IKEv2 VPN services offer enhanced security via end-to-end encryption, increased Internet speeds, a sturdier IPSec tunnel, and reduced bandwidth requirements.

What is IKE in the First Place?

IKE stands for Internet Key Exchange, which you may already know if you compare Wireguard vs OpenVPN. IKE is a protocol used to set up secure communication channels between two locations, such as when comparing a DNS vs a VPN. This is primarily to encrypt traffic for increased privacy, which is not the case when comparing a LAN vs a VPN. In addition to IKE, some VPNs create their own protocols from the ground up if you are comparing PPTP vs L2TP.

Insider Tip

Very few free VPNs allow access to IKEv2, so if you want these benefits, go with a paid VPN.

Differences Between IKEv2 and IKEv1

The two are extremely similar, as they are built using the same framework. However, IKEv2 was built as an answer to many of the limitations involved with using IKEv1 setups. With that in mind, IKEv2 is generally considered to be a better option in nearly every case. Here are some reasons why a security association typically opts for IKEv2.


If you rely on high Internet traffic speeds, go with a VPN that offers IKEv2. This protocol offers built-in support for NAT, making it quicker and easier to establish an initial connection. Also, IKEv2 supports Multi-homing Protocol (MOBIKE), and that further improves connection speeds, especially when switching between WiFi and a mobile network.


You’d think with all of the improvements, IKEv2 would certainly take up more bandwidth than its predecessor, but that is not the case. IKEv2 barely makes a chomp into the bandwidth compared to IKEv1, as it requires fewer security associations to establish a connection to a VPN tunnel.


Online privacy and overall network security also get a bump from IKEv2 over IKEv1. The newest iteration uses a number of leading encryption algorithms, whereas IKEv1 is stuck using some older algorithms. This gives IKEv2 access to high-end ciphers like Camellia, ChaCha20, and AES. Additionally, IKEv2 uses end-to-end encryption on both sides of the connection, which is something IKEv1 was not designed to do.

STAT: In IKEv2 Tunnel endpoints exchange fewer messages to establish a tunnel. IKEv2 uses four messages; IKEv1 uses either six messages (in the main mode) or three messages (in aggressive mode). (source)

IKEv1 and IKEv2 FAQs

Is IKEv2 compatible with IKEv1?

No, the two are not compatible, despite being built on the same framework. In other words, implementations of IKEv2 are not compatible with IPsec traffic using an IKEv1 connection.

Is IKEv1 still secure?

IKEv1 is still a secure key exchange, though a less secure key exchange than IKEv2. Implementations of IKEv2 offer an increased encryption protocol suite for better security.

Does IKEv2 support aggressive mode?

The IKEv2 security association (SA) does not support an aggressive mode, as this IPsec SA was used to beef up some of the weaker features of IKEv1.
Lawrence Bonk Profile image