The dns application cache ttl command sets the maximum and minimum of the TTL of the cache of application domain name resolution.
The undo dns application cache ttl command sets the maximum and minimum of the TTL of the cache of application domain name resolution to the default value.
dns application cache ttl maximum max-value minimum minimum-value
undo dns application cache ttl
| Parameter | Description | Value |
|---|---|---|
| maximum max-value | Specify the maximum of the TTL of the cache of application domain name resolution. | The value is an integer ranging from 60 to 4294967295, in second. The default value is 86400. |
| minimum minimum-value | Specify the minimum of the TTL of the cache of application domain name resolution. | The value is an integer ranging from 60 to 4294967295, in second. The default value is 3600. |
The device sends requests of domain name resolution to the DNS server according to the TTL of the cache of application domain name resolution. If the TTL is too short, the CPU occupancy can increase. If the TTL is too long, the updates cannot be performed in time. The administrator can properly set the maximum and minimum of the TTL of the cache of application domain name resolution by running this command. If the default TTL of application domain names is less than the minimum TTL configured on the device, the device periodically resolves domain names to the DNS server based on the configured minimum TTL. If the default TTL of application domain names is between the minimum and maximum TTLs configured on the device, the default TTL is retained. If the default TTL of application domain names is greater than the maximum TTL configured on the device, the device periodically resolves domain names based on the configured maximum TTL.