Configuring IPSec VPN on Cisco IOS


Configuring Site to Site IPSec VPN Tunnel Between Cisco Routers
R2 is just a router in the middle so that R1 and R3 are not directly connected. Hi , what is the ios image and version used in this lab? Lefty p Protocol [ip]: I was searching all around for an easy way to setup ipsec site to site VPN. Hi all I struggle with Cisco, but this article has really helped. Created by elpollodiablo on

How IPSec works on a Cisco router

Configure Site to Site IPSec VPN Tunnel in Cisco IOS Router

Created a peer struct for Next payload is 0. SA has been authenticated with Trying to insert a peer Checking IPSec proposal 1. SA life type in seconds. SA life type in kilobytes. IPSec policy invalidated proposal with error Checking IPSec proposal 2. Interface Virtual-Access2, changed state to up.

Line protocol on Interface Virtual-Access2, changed state to up. There seems to be a typo in the above example: L2TP-Set is not defined in the above configuration so the command should be: What about split tunnelling?

How do we account for that? Once the VPN is established, I am unable to browse internet on the client Please rate the answer if it was helpful or mark it as answered if it resolved your issue so that others can take the benefit out it as well. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Phase 1 and Phase 2. Phase 2 creates the tunnel that protects data. IPSec then comes into play to encrypt the data using encryption algorithms and provides authentication, encryption and anti-replay services. Our example setup is between two branches of a small company, these are Site 1 and Site 2. Site 1 is configured with an internal network of The goal is to securely connect both LAN networks and allow full communication between them, without any restrictions. This means that if we have five different remote sites and configured five different ISAKMP Phase 1 policies one for each remote router , when our router tries to negotiate a VPN tunnel with each site it will send all five policies and use the first match that is accepted by both ends.

Next we are going to define a pre shared key for authentication with our peer R2 router by using the following command:.

Next step is to create an access-list and define the traffic we would like the router to pass through the VPN tunnel. In this example, it would be traffic from one network to the other, Access-lists that define VPN traffic are sometimes called crypto access-list or interesting traffic access-list. Next step is to create the transform set used to protect our data. R2 is just a router in the middle so that R1 and R3 are not directly connected. We use DH group For each peer we need to configure the pre-shared key.

And put everything together with a cryptomap. Our peer is We need to make sure our router knows how to reach You may cancel your monthly membership at any time. The authentication pre-share command indicates that a pre-shared key will be used configured manually on each device as the method by which the devices will establish the identity of each other as an IPsec peers.

The group 2 command on the other hand indicates the use of Group 2 Diffie-Hellman identifier to derive a shared symmetric secret without transmitting it. This is used for the purpose of encryption.

Steps to configure an IPSEC site to site VPN on a Cisco IOS device (GNS3 Lab)