force-ip-preference

This command sets whether to restrict DNS queries to the preferred IP version.

Syntax

force-ip-preference { on | off }

Parameters

on

Sends DNS queries to only the preferred IP version: A (IPv4) or AAAA (IPv6) record. This setting avoids latency with unneeded IPv6 queries in IPv4-only environments and vice versa.

off

Sends DNS queries for both A and AAAA records. This setting is the default setting.

Guidelines

The force-ip-preference command sets whether to restrict DNS queries to the preferred IP version. You want to force the IP preference except when both IPv4 and IPv6 addresses are in use. When not forced, the appliance resolves each host name by querying A and AAAA records and waiting for both responses or a timeout. Waiting for the response or timeout for both records can introduce unnecessary latency in DNS resolution.

To set the preferred IP version, use the ip-preference command.