Linksys Router Security?

[parias]

I have tried to change my IP various times and it just won't do it. I called my internet provider and he said to just wait for the lease time and the IP will change. I waited and it did not change. I keep getting pinged by other people (I've been told they are using something called a shell). Is there anyway to protect against this? If so please let me know. As I cannot change my IP I would like to be able to protect against it.