Hello,
This question is more about curiosity and not a top priority exam question (no problem if answered later). I was wondering: in slide 21 of ip2 slides, we are told that some firewalls kill the IP in IP packets. That's why we add a layer and put IP packet in UDP segment.
- I'm not sure I understand the firewall config rationale behind the killing of IP in IP packets. If this is trivially solved by putting IP in UDP, why firewalls are happier this way?
- Why is there the need for putting the L2TP/PPP header? It is said we must add a layer 2 protocol, but couldn't this one be added by the normal routing (frame read and replaced by routers from a subnet to another)?
Thanks!