Tag Archives: domain name

Red Hat Certification – RHCE – Network Services – DNS

1st post – System Management and Configuration

Objectives

Network services

Network services are an important subset of the exam objectives. RHCE candidates should be capable of meeting the following objectives for each of the network services listed below:

  • Install the packages needed to provide the service.
  • Configure SELinux to support the service.
  • Configure the service to start when the system is booted.
  • Configure the service for basic operation.
  • Configure host-based and user-based security for the service.

User should be able to do the following for all these services:

DNS:

A DNS-server is quite easy to test as well, just point a client to the IP of your local DNS server and check /var/log/messages on the DNS-server.

  • Install the packages needed to provide the service.
    • yum install bind
  • Configure SELinux to support the service
    • working from scratch, after adding new zones and things you may need to add correct context to the files
  • Configure the service to start when the system is booted.
    • chkconfig named on
  • Configure the service for basic operation.
    • /etc/named.conf
      • after editing you need to restart named
    • edit ‘allow-query’ and ‘listen-on port 53’ – update firewall, start named
    • configure a client to use it with /etc/resolv.conf
    • see examples in: /usr/share/doc/bind*/
  • Configure host-based and user-based security for the service
    • host-based can be done via firewall (port 53 UDP and TCP)
    • host-based: allow-query { localhost; };
    • but user-based??

Extra

  • Configure a caching-only name server.
    • This is what the default /etc/named.conf does it – (this is also stored in the /usr/shar/doc/bind*/ – but, it a good thing to try would be to try to configure this from an empty named.conf
  • Configure a caching-only name server to forward DNS queries.
    • Almost same config as caching-only, except for the addition of two lines:
      • forward only;
      • forwarders  { dns.ip; dns.ip2 }
  • Note: Candidates are not expected to configure master or slave name servers.