DNS Client Configuration Mode Commands

DNS Client Configuration Mode Commands
 
The DNS Client Configuration Mode is used to manage the system’s DNS interface and caching parameters.
note_smallImportant: The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
bind
Binds the DNS client to a pre-configured logical IP interface.
Product
MME, SCM, SGSN
Privilege
Security Administrator, Administrator
Syntax
bind { address ip_address [ port number ] | query-over-gtp }
no bind address
no
Removes the binding of the client to a specified interface.
bind address ip_address
Specifies the IP address of the interface to which the DNS client is being bound in IPv4 dotted-decimal notation.
bind port number
Specifies the UDP port number of the interface to which the DNS client is being bound as an integer from 1 to 65535. Default: 6011
bind query-over-gtp
Specifies that DNS client query is to be performed over GTP.
Usage
Use this command to associated the client with a specific logical IP address.
Example
The following command binds the DNS client to a logical interface with an IP address of 10.2.3.4 and a port number of 6000:
bind address 10.2.3.4 port 6000
cache algorithm
Configures the method of use for the DNS VPN and session cache.
Product
MME, SCM, SGSN
Privilege
Security Administrator, Administrator
Syntax
cache algorithm { central | local } { FIFO | LRU | LFU }
default cache algorithm { central | local }
default
Sets the DNS VPN and session cache method to default setting.
central | local
central: Specifies the central proclet (VPN manager)
local: Specifies the local proclet (session manager)
FIFO | LRU | LFU
FIFO: First in first out. This is the default setting for the central proclet.
LRU: Least recently used. This is the default value for the local proclet.
LFU: Least frequently used.
Usage
Use this command to configure the method by which entries are added and removed from the DNS cache.
Example
The following command configures the cache algorithm for the central proclet to least frequently used (LFU):
cache algorithm central lfu
cache size
Configures the maximum number of entries allowed in the DNS cache.
Product
MME, SCM, SGSN
Privilege
Security Administrator, Administrator
Syntax
cache size { central | local } max_size
default cache size { central | local }
default
Sets the maximum number of entries allowed in the DNS cache to default setting.
{ central | local } max_size
central max_size: Specifies the maximum number of entries allowed in the central proclet cache as an integer from 100 through 65535. Default: 50000.
local max_size: Specifies the maximum number of entries allowed in the local proclet cache as an integer from 100 through 65535. Default: 1000.
Usage
Use this command to configure the maximum number of entries allowed in the DNS cache.
Example
The following command configures the cache size of the central proclet to 20000:
cache size central 20000
cache ttl
Configures the DNS cache time to live (TTL) for positive and negative responses.
Product
MME, SCM, SGSN
Privilege
Security Administrator, Administrator
Syntax
cache ttl { negative | positive } seconds
default cache ttl { negative | positive }
no cache [ ttl { negative | positive } ]
no
Disables any or all configured DNS cache parameters.
default
Sets the DNS cache time to live for positive and negative responses to the default setting.
{ negative | positive } seconds
negative seconds: Specifies the time to live for negative responses as an integer from 60 through 86400. Default: 60.
positive seconds: Specifies the time to live for positive responses. as an integer from 60 through 86400. Default: 86400 (1 day).
Usage
Use this command to adjust the DNS cache time to live.
Example
The following commands set the TTL DNS cache to 90 seconds for negative responses and 43200 seconds for positive responses:
cache ttl negative 90
cache ttl positive 43200
case-sensitive
Configures the case sensitivity requirement for responses to DNS requests.
Product
MME, SCM, SGSN
Privilege
Administrator
Syntax
[ default | no ] case-sensitive response
default
Returns the command to its default setting of disabled.
no
Disables the requirement for case sensitivity in DNS responses.
case-sensitive response
Enables the requirement for case sensitivity in DNS responses.
Usage
Use this command to require case sensitivity (identical case usage between request and response) on all responses to DNS request messages.
end
Exits the current configuration mode and returns to the Exec mode.
Product
All
Privilege
Security Administrator, Administrator
Syntax
end
Usage
Use this command to return to the Exec mode.
exit
Exits the current mode and returns to the parent configuration mode.
Product
All
Privilege
Security Administrator, Administrator
Syntax
exit
Usage
Use this command to return to the parent configuration mode.
resolver
Configures the number of DNS query retries and the retransmission interval once the response timer expires.
Product
MME, SGSN
Privilege
Security Administrator, Administrator
Syntax
resolver { number-of-retries retries | retransmission-interval time }
default { number-of-retries | retransmission-interval }
default
Resets the specified resolver configuration to the default.
number-of-retries retries
Configures the number of DNS query retries on DNS response timeout as an integer from 0 through 4. Default: 2.
retransmission-interval time
Configures the initial retransmission interval (in seconds) for retransmission after the DNS response timeout as an integer from 2 to 5. Default is 3 seconds. The retransmission interval doubles after each retry when only one server is configured. In case both primary and secondary servers are configured, the retransmission time is doubled for the last retry.
Usage
Set the DNS retransmission retries or the retransmission interval. Issue the command twice to configure both parameters, one-at-a-time.
Example
The following command sets the DNS resolver retries to 4:
resolver number-of-retries 4
round-robin answers
Configures the DNS client to return the DNS results in round-robin fashion if multiple results are available for a DNS query.
Product
MME, SGSN
Privilege
Security Administrator, Administrator
Syntax
[ no | default ] round-robin-answers
no
Removes the configured round robin method for DNS answer.
default
Disables the round robin method for DNS answer.
round-robin-answers
Enables the round robin method for DNS answer.
Usage
Use this command to configure the DNS client to return the DNS results in round-robin fashion if multiple results are available for a DNS query.
Example
The following command configures the DNS client to use round robin method for DNS query answers:
default ] round-robin-answers
 
 
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