IPsec protocol

IPsec Protocol Breakdown

Many different providers can establish many different VPN protocols. One of the most popular and security-focused is called IPsec. IPsec is broken down into 4 main sub-protocols that enable it to create and sustain a secure connection. Below is a quick review the main protocols within IPsec and explain how they are fit together.

IPsec Sub-Protocols IPsec was the main protocol effort to account for missing security controls within the IPv4 once IPv6 was released. There are several vital protocols that IPsec has brought to the table to ensure better connection security. First is the IP authentication header (AH), which is an additional header field that provides information around the origin of the authentication for IP packets, thus guaranteeing connection integrity. To take AH a step further, IPsec has incorporated ESP or IP Encapsulating Security Payload which provides even more protection through the optional header in the means of access controls, authentication origin as well as integrity protection. Both AH and ESP combined provide you with optimal protection against traffic sniffing and replay attacks.

The next added benefit was the Internet Key Exchange or IKE and its sequential next version IKEv2. The primary focus of IKE is to provide a means to define whitelist services within the packet and provide a method for key sharing as well.

The last protocol to identify is ISAKMP or the Internet Security Association and Key Management Protocol. ISAKMP is considered an advancement add-on to the IKE protocol, and its primary purpose is to determine best how different security entities are to be set up for a secure connection while using IPsec. This protocol is one of the most important in the IPsec suite as it acts as the “smart” protocol, thus directing the traffic for all communication between the other protocols.

How IPsec works

There are 5 general steps that makeup IPsec with some additional options in between that can be established depending on your use case.

Step 1 is when the sending host makes the argument that a packet should be sent via IPsec, which is done by checking the IP address against what has been called out in the IPsec policy.

Step 2 is when IKE steps and only allow the two hosts to communicate enough to establish a shared policy for communication, once established, and then a secure full connection is set.

Step 3 is when IKE negotiates the Key management and crypto algorithm to be used for the secure connection. IKE is essential to enable either side to decipher the message packets being sent back and forth. Remember, a secure connection can be set without it being able actually to be used.

Step 4 is the actual payload of the connection and where the magic happens. By sending the contents of the message over the encrypted channel and effectively having it encrypted and decrypted on both sides.

Step 5 is the termination of the connection when either the number of bytes defined has been met, or the session is terminated by one side. At this point, all encryption keys are discarded, and new ones would be established for the next connection.

This whole process happens within fractions of a second for every exchange, but it is essential to know that your VPN service provider is fully capable of implementing IPsec and all of its options to ensure a secure connection at all times. Consider a professional team like RingVPN for all of your VPN needs.