IKEv2 VPN Protocol Explained: What It Is and How It Works

Miklos Zoltan

By Miklos Zoltan . 27 January 2024

Founder - Privacy Affairs

Justin Oyaro

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Internet Key Exchange version 2 (IKEv2) is among the fastest vpn protocols. It is usually paired with IPSec and is commonly known as IKEv2/IPSec.

The VPN protocol is widely implemented in mobile devices. This can be attributed to its fast speeds, stability, and high reliability when switching between networks.

Quick Summary

IKEv2 is a tunneling protocol within the IPSec protocol suite. It is responsible for setting up Security Association (SA) for secure communication between VPN clients and VPN servers within IPSec.

IKEv2 is a successor to IKEv1 and was jointly developed by Microsoft and Cisco.

Looking for an IKEv2 VPN? – Try ExpressVPN. ExpressVPN is the #1 rated and fastest IKEv2 VPN currently available.

Read below to learn more about IKEv2.


How Does IKEv2 Work?

IKEV2 heavily relies on IPSec to secure the communication between a VPN client and a VPN server.

This explains why the protocol is often identified as IKEv2/IPSec. Simply put, IKEv2/IPSec secures and allows the exchange of encryption keys – true to its name.

In a nutshell, IKEV2 sets up a security association (SA) that negotiates security keys used by both the VPN client and the VPN server.

Once IKEv2 validates the security association, a secure tunnel is set, which prompts encrypted communication between the two peers.

IKEv2/IPSec uses the more robust 256-bit encryption. It can use VPN encryption ciphers such as AES, ChaCha20, and Camellia.

The VPN protocol also uses the famous Diffie-Hellman Key Exchange algorithm to secure private key exchange.

It’s also worth knowing that:

  • IKEv2 supports Perfect Forward Secrecy (PFS) for data integrity and complete secrecy.
  • IKEv2/IPSec uses UDP packets as well as port 500.
  • IKEv2 uses X.509 certificates for authentication.
  • IKEv2 integrates well with open-source software like OpenIKEv2, StrongSwan, OpenSwan, and more.

Why is IKEv2 Always Paired with IPSec?

It is all about security, speed, and stability. IPSec is considered secure and reliable, while IKEv2 is extremely fast and stable – IKEV2 offers quick re-connections when switching networks or during sudden drops.

Thus, a combination of IKEv2/IPsec forms one of the best VPN protocols that exhibits the advantages of the two.

IPSec protocol suite creates secure tunnels between two communicating peers over a network. The protocol is also used to encrypt data in VPNs.

Moreover, IPSec uses an array of techniques for authentication and key exchange for negotiating security associations. One of these includes Internet Key Exchange (IKE and IKEv2).

Why is IKEv2 Considered Better than IKEv1?

IKEv2 is the successor of IKEv1, with improvements and optimizations such as fast speeds, greater security, and increased efficiency.

Here is a highlight of the features of the improved IKE version 2:

  • IKEv2 supports more encryption algorithms, including Asymmetric authentication
  • IKEv2 is more stable thanks to its support for Mobility and Multi-homing Protocol (MOBIKE)
  • IKEv2 uses fewer bandwidth data by using a reduced number of security associations needed
  • IKEv2 features a built-in NAT traversal which enables it to pass through firewalls
  • IKEv2 can determine if a tunnel is active, thanks to its ‘keep alive’ feature that’s always enabled
  • IKEv2 supports an authentication technique called Extensible Authentication Protocol (EAP) that secures communication
  • IKEv2 is highly reliable, thanks to its enhanced number sequence and acknowledgments
  • IKEv2 is more resistant to DoS attacks because of its ability to check and determine if a requester exists before it takes any action

IKEv2 Compatibility

IKEv2 supports all major platforms, including Windows, macOS, Android, iOS, Linux, and routers.

It’s especially fast on macOS, making IKEv2 VPNs great choices if you are looking for a Mac VPN.

The protocol is also compatible with smart devices like Smart TVs and some streaming devices.

Most VPN providers offer IKEv2/IPSec as a default protocol on their client apps due to its advanced security, stability, and reliability levels.

Benefits of the IKEv2/IPSec Protocol

  • Very fast, regardless of using strong encryption levels.
  • Very secure as it uses multiple advanced ciphers for maximum protection.
  • Very stable thanks to its seamless auto-reconnect feature let users switch between networks without dropping protection or connection.
  • Compatible with all major platforms and devices.

Disadvantages of the IKEv2/IPSec Protocol

  • IKEv2 is closed source, thus raising slight security concerns, coupled with its links to Microsoft and Cisco. Some implementations are open source.
  • IKEv2 can be exploited since it is built upon ISAKMP.

2024 Update: The IKEv2 (Internet Key Exchange version 2) VPN protocol continues to be recognized for its speed and security, making it a highly recommended choice for VPN users. It’s advisable to opt for IKEv2 whenever you’re using a VPN for optimal performance and enhanced security.

Frequently Asked Questions

Some people found answers to these questions helpful

What is IKEv2 used for?

Internet Key Exchange version 2 (IKEv2) is a VPN protocol that offers a secure tunnel for communication between two peers over the internet. It negotiates security associations (SAs) within an authentication protocol suite of IPSec. The two form a formidable VPN protocol widely called IKEv2/IPSec.

Is IKEv2 a suitable VPN protocol?

Yes, thanks to its fast connection speeds, IKEv2/IPSec is considered a great VPN protocol. The VPN protocol is also rated highly since it uses strong encryption standards like the best-in-class AES-256 ciphers. IKEv2 also uses the Diffie-Hellman Key Exchange algorithm to exchange keys securely.

Is IKEv2 good for gaming?

Yes, IKEv2 is an excellent protocol choice for gamers, thanks to its fast speeds, stability, and high security. The VPN protocol also utilizes low latency levels, a feature that works very well with online games worldwide.

How secure is IKEv2?

IKEv2 uses the best-in-class 256 encryption and supports an array of cryptographic algorithms like AES, Blowfish, and Camellia. IKEv2 alone also has no known vulnerabilities unless implemented poorly.

Is IKEv2 better than other VPN protocols?

IKEv2 is better than most VPN protocols regarding performance and efficiency, especially on mobile devices. Other than robust security and fast speeds, IKEv2 uses fewer CPU resources (consumes less battery), and it is stable when switching between networks (re-establishes connections in a quick manner).


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  • Charles

    March 8, 2023 12:33 pm

    This is an excellent IKEv2 review.
    As an “EndUser” I can say I got it.
    Express VPN de[ploys IKEv2 along with other protocols.
    I choose IKEv2 for it’s supreme encryption abilities;
    Best used while Banking, Making online purchases, creating a secure communication. Add PGP with that if you like.
    As an endUser I trust the “WhiteHatter’s” to keep their watchful eyes on closed
    source code.
    In the 1980’s Microsoft added SQL Server to it;s operating systems.
    I was using my favorite Windows ME. I had that OS rippin the internet.
    During those years of the Microsoft SQLServer System, what no one knew was that SQL Server was Bill Gates “BackDoor” into any PC running windows, any time, anywhere, the whole wide internet world.
    It was then a lovely group of Black Hat Hackers, verses it’s antithisis WhiteHat Hackers, well this black group was Black. “CultOfTheDeadCow’ A black hat hacker group located in New York City’s Harlem .
    Those Black boys and girls discovered Bill Gates BackDoor, reversed engineered it, and saint a personal message to Bill Gates and his inner circle that was not nice . As the “CultOfDeadCow’ understood Federal law concerning Hacking at that time , you could enter anyones personal or corporate machine provided you did not change one iota of it’s OS nor anything else. You could leave a message on their “DeskTop”, which was what ” CDC” marvelously did.
    HuRah “CDC”
    Where are they today? find out if you live dangerously.

  • Deborah

    September 25, 2022 6:13 pm

    I barely understand any of this except the basic messages. . Thanks to this article I will turn on the VPN on my iPhone. Thank you!

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