Setting up a Cisco router for terminating Microsoft L2TP IPSec sessions

For this example i used a Cisco 1841 running c1841-advsecurityk9-mz.124-3i.bin

Remote User connects to gate’s puplic reachable IP with his Microsoft L2TP IPSec client (Windows 2000 and higher)
After successful authentication, the Client gets an IP address from local pool
MS L2TP-IPSec-Client adds a default route over the new PPP interface (but you can deactivate it)

Here’s the template for router [...]

Using EIGRP with IPSEC encrypted GRE tunnels

In one of my last posts, GRE tunneling with IPSec encryption, i explained the setup of a simple ipsec-protected GRE connection.
When your network is a little bit larger than my test scenario, you would prefer to use an dynamic routing protocol between your routers (hilde and maria in my case).
Nothing easier than that….
Here’s an example using [...]

GRE tunneling with IPSec encryption

Some times ago, a frequently mentioned feature in networking blogs was “GRE tunneling with IPSec encryption”. I tried it out and found it awesome.  (in the meanwhile, we use it in production) . When i need encrypted communication between to endpoints, i would prefer IPSec-encrypted GRE rather than Site-to-Site IPSec-VPN because:

its easier to configure (no longer [...]