How To Configure IP Sec crypto isakmp on router

[Bharat Sharma]

Hi,

I want to configure IP Sec crypto isakmp on router P2P link interface which is connected to the firewall for secure traffic & data. I want allow selected IP address & subnet on this interface

[Georg Pauwen]

Hello,

with OSPF, it is better to use an (S)VTI setup, which doesn't involve crypto maps and split tunnel access lists (and is actually a lot easier to configure).

Post the full config of your 4451, so we can fill in the necessary bits and pieces...

[sbhadrav@cisco.com]

To help make this an easy-to-follow exercise, we have split it into two steps that are required to get the Site-to-Site IPSec VPN Tunnel to work.

These steps are:

(1)  Configure ISAKMP (ISAKMP Phase 1)

(2)  Configure IPSec  (ISAKMP Phase 2, ACLs, Crypto MAP)

Our example setup is between two branches of a small company, these are Site 1 and Site 2. Both the branch routers connect to the Internet and have a static IP Address assigned by their ISP.
Site 1 is configured with an internal network of 10.10.10.0/24, while Site 2 is configured with network 20.20.20.0/24. The goal is to securely connect both LAN networks and allow full communication between them, without any restrictions.