Cisco Router Specification regarding VPN Tunnels

Just to help not to be confused, like me... Long time ago I faced an issue regarding the limit of VPN tunnels on Cisco 3800 series router. In the specification you read :

• Up to 2500 VPN tunnels

I had a 3845 router with around 700 VPN Tunnels, but the router was not able to manage the tunnels and they were flapping non-stop! I looked long time for the source of problem until the time that I decided to reduce the number of tunnels with the batch of 20 tunnels. I got the stability when I reached a specific number of tunnels in the router.

LMS4.2 ESC RICS0001:Internal Error,unable to process the collected data from the device

In LMS4.2, you may get the error message "ESC RICS0001:Internal Error,unable to process the collected data from the device" when your device platform is changed. For example, when you replace a router and you do the inventory! The reason is that LMS is not able to find the old index and in consequence, the inventory can't be gathered successfully.

I reported the issue to Cisco July 2012 and in November 2012 they created a development case with the bug ID CSCud15801. 

Visualize logs real time in Linux

With the following command you can visualize the logs real time in Linux:

tail -f FILENAME

If you want to filter in real time logs, tail and grep can be combined:

tail -f FILENAME | grep FILTER

Logical AND and OR with grep

I am not that much familiar with Linux and Unix, but I find these commands so helpful when you parse the logs.
To do a logical OR, you can use one of the following commands:
grep -i -E "Var1|Var2" FILENAME 

awk '/Var1/ || /Var2/' FILENAME

To do a logical AND, you can use the following command:
grep VAR1 FILENAME | grep VAR2 | grep VAR3

awk '/Var1/ && /Var2/' FILENAME

APs do broadcast on port UDP 5246

If you have an access list for your access points or there is a firewall between your APs and your wireless controller, you may see APs attempting broadcast (255.255.255.255) on port UDP 5246. In order to get rid of these broadcasts, you need to specify the primary controller for your APs, even though you have only one controller in your network.
In order to do that, you need to click on your AP in wireless controller, click on "High Availability" tab, and type the name and IP address of your primary controller. (The path is for WLC 5508)