l to learn these topics? I mean I just want to learn this exact chapter from a book, what topics should I seek? I am trying to implement it on k3s.
https://d3s.mff.cuni.cz/teaching/nswi106/202324/reading/internetworking/
Something like this could prove beneficial. I prefer academically written textbooks.
NAT is a tricky thing, though. Used one time with the Internet connection, it is manageable. If it is used a second time for masking internal traffic, then problems develop. Problems multiply if address spaces are re-used in different areas and NAT is employed to mask the IP address re-use. This last scenario is common in industrial environments.
In the K3S cluster, how many nodes are being used? If the number is over 64K, then we may want to instead go with IPv6 instead of IPv4 with NAT.