Chapter 18. DNS/DHCP

Name resolution and the dynamic assignment of IP addresses, whether from the perspective of the firewall as a dynamic device or as the DHCP address provider itself, poses several problems. These can include issues with updating firewall rules in a dynamic environment, such as cable modems and DSLs to DMZs for DHCP servers. In this chapter, we will cover some of the more common issues with getting DNS to work on or through firewalls as well as one more bizarre configuration involving getting console games to work over the Internet (we’re not kidding).

Common Questions

Q:

Can you use hostnames instead of IP addresses?

A:

Yes, you can; however, when the rules are initially loaded, netfilter will perform a lookup on those names and ...

Get Troubleshooting Linux® Firewalls now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial