Configuring DNS

This section provides details for the configuration of DNS resolution on the S- K- and 7100-Series products.

Default DNS Parameters lists DNS parameters and their default values.

Default DNS Parameters

Parameter	Description	Default Value
DNS resolver state	Specifies whether DNS resolver is enabled or disabled on the device.	enabled
DNS zone	Specifies the DNS zone for IPv4 and IPv6.	IPv4 - in-addr.arpa IPv6 - ip6.arpa
DNS port	Specifies the port number the DNS resolver uses for DNS queries.	53
timeout	Specifies the number of seconds before a DNS request is retried when the DNS server fails to respond.	10 seconds
query-retries	Specifies the number of times to retry a lookup request to a DNS server that has failed to respond.	2

Configuring DNS Resolution describes how to configure DNS resolution. DNS can be configured in any CLI command mode.

Configuring DNS Resolution

Step	task	Command(s)
1	Enable DNS on the switch if you have manually disabled it. DNS is enabled by default.	set ip dns enable
2	Optionally, set the domain name for this device.	set ip dns domain name
3	Configure the DNS servers for this device. Valid server values are: primary, secondary, tertiary, quaternary.	set ip dns server ip-address server
4	Optionally, configure the DNS zone for IPv4 and IPv6 IP address to name lookups.	set ip dns zone {ipv4 | ipv6} zone-name
5	Optionally, configure the port number the DNS resolver uses for DNS queries. The default port is 53.	set ip dns port-number port-number
6	Optionally, change the number of seconds before a DNS request is retried when the DNS server fails to respond.	set ip dns timeout seconds
7	Optionally, change the number of times to retry a lookup request to a DNS server that has failed to respond.	set ip dns query-retries retries

Managing DNS Resolution describes how manage DNS resolution on an S- K- and 7100-Series switch. DNS commands can be configured in any CLI command mode.

Managing DNS Resolution

Task	Command(s)
To clear the DNS domain name configuration.	clear ip dns domain
To clear the DNS server configuration.	clear ip dns server [server | all]
To reset the DNS IPv4 or IPv6 zone configuration.	clear ip dns zone [ipv4 | ipv6]
To reset the DNS port number used for DNS queries to the default value.	clear ip dns port-number
To reset the DNS timeout to the default value.	clear ip dns timeout
To reset the number DNS query retries to the default value.	clear ip dns query-retries
To clear all DNS configuration to the default state.	clear ip dns all
To reset DNS status for this device to the default value.	clear dns status
To display DNS configuration for this device.	show ip dns