You specifically want Linux so I would skip all the generic or cisco focused books. Have you read LDD3? http://www.makelinux.net/ldd3/ http://www.makelinux.net/

You specifically want Linux so I would skip all the generic or cisco focused books. Have you read LDD3? http://www.makelinux.net/ldd3/ http://www.makelinux.net/ldd3/ ,chapter 17 specifically. It's difficult to learn the Linux network stack without knowing C as well.