Category: Domain Name Service (DNS)

  • Setting up a classless DNS with Bind9 on Ubuntu and Red Hat Linux flavors

    Setting up a classless DNS is critical if you are setting up a mail server on your classless set of IPs. For instance, when my mail users send e-mails to Comcast, Cox, or Time-Warner, my mail is rejected with the following message between the stars: ******************** Subject: Undelivered Mail Returned to Sender This is the […]

  • Linux overwrites DNS resolver /etc/resolv.conf

    Linux will overwrite your /etc/resolv.conf in 3 cases. If you have: Network Manager enabled. Disable the Network Manager by turning it off with the following commands: >service NetworkManager stop >chkconfig NetworkManager off         DHCP enabled. dhcpd will overwrite your /etc/resolv.conf when it acquires an IP address. Convert to a static IP if you are in control of […]