GRE Encryption with IPSec | VPN Tunnels Part 2

GRE Encryption with IPSec | VPN Tunnels Part 2

GRE tunnels do not have any native encryption! Fortunately, you can add IPSec encryption in transport mode to your tunnel.

First, we’ll have a quick look at how IPSec works. IPSec uses two security tunnels (called phase-1 and phase-2) for authentication, cipher and hash proposal, and session key exchange.

Some of the protocols used in this process include ESP (Encapsulating Security Payload), IKE (Internet Key Exchange), ISAKMP, AH (Authentication Header), and the Diffie-Hellman algorithm.

Once both sides agree on how these protocols will work, they will have built an SA (Security Association)

If you have NAT in your network, IPSec can detect and work around it with NAT-T

Try it yourself in the lab!

Part 1: How GRE Works - See the encapsulation process, as a packet moves from one side of the network to another

Part 2: GRE Encryption with IPSec - GRE is not encrypted by default! See the basics of IPSec, and how we can use it with GRE tunnels

Part 3: Improving GRE Stability - There are a few pitfalls to watch out for, including recursive routing. See some of the best practices that you can apply to make your tunnel stable

This video is useful for Cisco #CCNA and #CCNP certifications

[meinbherpieg]

Clear, Concise, and, say it with me, HOLISTIC. Good job.

[sajjadmisrikoti]

You make topics look simple..excellent

[prasadtalekar]

I love the way you explain using animation ..its better way to understand and also build imagination

[RyanBreaker]

This is the best guide I've found on the topic yet. Any chance for a video or article on DMVPN?

[ВГаража]

Excellent guide! Thank you very much! Please keep up with the good work!

[TheRedmansk]

This maybe a dumb question will this method work with a Cisco 1921 k9\sec router when setting up gre tunnels with ipsec?