ZyXEL Communications UAG Series - DNS Commands; DNS Overview; Domain Zone Forwarder

Chapter 56 System
UAG CLI Reference Guide
276
56.6 DNS Overview
DNS (Domain Name System) is for mapping a domain name to its corresponding IP address and
vice versa. The DNS server is extremely important because without it, you must know the IP
address of a machine before you can access it.
56.6.1 Domain Zone Forwarder
A domain zone forwarder contains a DNS server’s IP address. The UAG can query the DNS server to
resolve domain zones for features like VPN, DDNS and the time server. A domain zone is a fully
qualified domain name without the host. For example, zyxel.com.tw is the domain zone for the
www.zyxel.com.tw fully qualified domain name.
56.6.2 DNS Commands
The following table identifies the values required for many of these commands. Other input values
are discussed with the corresponding commands.
The following table describes the commands available for DNS. You must use the
configure
terminal
command to enter the configuration mode before you can use these commands.
Table 175 Input Values for General DNS Commands
LABEL DESCRIPTION
address_object The name of the IP address (group) object. You may use 1-31 alphanumeric characters,
underscores(
_), or dashes (-), but the first character cannot be a number. This value is
case-sensitive.
interface_name The name of the interface. This depends on the UAG model.
See Table 37 on page 86 for detailed information about the interface name.
Table 176 Command Summary: DNS
COMMAND DESCRIPTION
[no] ip dns server a-record fqdn w.x.y.z Sets an A record that specifies the mapping of a fully qualified
domain name (FQDN) to an IP address. The
no command deletes
an A record.
ip dns server cache-flush Clears the DNS records.
ip dns server max-ttl <10..3600> Sets the maximum TTL (Time to Live) value for DNS records.
[no] ip dns server mx-record domain_name
{w.x.y.z|fqdn}
Sets a MX record that specifies a mail server that is responsible for
handling the mail for a particular domain. The
no command
deletes a MX record.
ip dns server rule {<1..32>|append|insert
<1..32>} access-group {ALL|address_object}
zone {ALL|address_object} action {accept|deny}
Sets a service control rule for DNS requests.
ip dns server rule move <1..32> to <1..32> Changes the number of a service control rule.