Patton electronic SmartNode 4110 Series manual 307

SmartWare Software Configuration Guide 28 • DNS configuration

address. DNS Relay agents maintain a cache of host names and IP addresses, much smaller than a DNS Server. It acts as a liaison between the DNS Server and the DNS client

Advantages in configuring a DNS Relay in the SmartNode are:

•Network traffic is reduced since only a single query is sent to the DNS server although numerous users may be requesting an IP address for the same host name

•The DNS queries are localized between the Users and the SmartNode which reduces congestion on the WAN side of the SmartNode

•Multiple DNS servers can be consulted from the SmartNode

The DNS resolver must be configured before you can use the DNS relay feature (see section “Enabling the DNS resolver” on page 305 to enable the DNS resolver, if you have not already done so).

Do the following to enable the DNS relay feature:

Mode: Configure

Step	Command	Purpose
1	node(cfg)#dns-relay	Enables DNS relay feature

Example: Enabling DNS relay

The following example shows how to enable the DNS relay feature.

node>enable

node#configure node(cfg)#dns-relay

Note If a DHCP server profile has been set up, you can announce the SmartNode as domain name server to the DHCP clients as follows:

node(cfg)#profile dhcp-server LAN node(pf-dhcps)[LAN]#domain-name-server <ip-address>

Where ip-addressmust be the IP address of the SmartNode IP interface to which the DHCP clients are connected.

DNS configuration task list 307