1장. Setting up and configuring a BIND DNS server
BIND is a feature-rich DNS server that is fully compliant with the Internet Engineering Task Force (IETF) DNS standards and draft standards. For example, administrators frequently use BIND as:
- Caching DNS server in the local network
- Authoritative DNS server for zones
- Secondary server to provide high availability for zones
To secure a BIND installation, you can:
Run the
namedservice without a change-root environment. In this case, SELinux inenforcingmode prevents exploitation of known BIND security vulnerabilities. By default, Red Hat Enterprise Linux uses SELinux inenforcingmode.중요Running BIND on RHEL with SELinux in
enforcingmode is more secure than running BIND in a change-root environment.Run the
named-chrootservice in a change-root environment.By using the change-root feature, administrators can define that the root directory of a process and its sub-processes is different to the
/directory. When you start thenamed-chrootservice, BIND switches its root directory to/var/named/chroot/. As a consequence, the service usesmount --bindcommands to make the files and directories listed in/etc/named-chroot.filesavailable in/var/named/chroot/, and the process has no access to files outside of/var/named/chroot/.
If you decide to use BIND:
-
In normal mode, use the
namedservice. -
In a change-root environment, use the
named-chrootservice. This requires that you install, additionally, thenamed-chrootpackage.