Change TCP/IP Domain (CHGTCPDMN)

Change Local Domain and Remote DNS information

Use the Change TCP/IP Domain Information (CHGTCPDMN) command to specify this system's TCP/IP host and domain name and to configure the Domain Name Server (DNS) information for this system.

Restrictions:

You must have input/output system configuration (*IOSYSCFG) special authority to run this command.

Parameters

Keyword	Description	Choices	Notes
HOSTNAME	Host name	Character value, SAME, NONE	Optional
DMNNAME	Domain name	Character value, SAME, NONE	Optional
DMNSCHLIST	Domain search list	Character value, SAME, DFT	Optional
HOSTSCHPTY	Host name search priority	REMOTE, LOCAL, *SAME	Optional
INTNETADR	Domain name server	Element list	Optional
	Element 1: Internet address	Character value, SAME, NONE
	Element 2:	Character value, SAME, NONE
	Element 3:	Character value, SAME, NONE
PORT	Port	1-65535, *SAME	Optional
PROTOCOL	Protocol	UDP, TCP, *SAME	Optional
INLDMNSVR	Initial domain name server	FIRST, ROTATE, *SAME	Optional
DMNSVRRTY	Domain name server retry	Element list	Optional
	Element 1: Number of retries	1-99, *SAME
	Element 2: Time interval	1-99, *SAME

Top

Host name (HOSTNAME)

Specify the TCP/IP host name of this system.

Note: This system's TCP/IP host name must also be defined in the local host table or the Domain Name Server (DNS) specified in the INTNETADR parameter. If no Domain Name Server (DNS) is specified, the local TCP/IP host table is used.

*SAME: The TCP/IP host name does not change if it was previously set.
*NONE: No host name is defined for this system.
character-value: Specify a TCP/IP host name for this system.

Example of how to use the HOSTNAME parameter to specify a TCP/IP host name where "asac1" is the name of the local system:

   CHGTCPDMN HOSTNAME ('asac1')

Domain name (DMNNAME)

Specify the name of the TCP/IP domain this i5/OS host is a member of.

*SAME: The TCP/IP domain name does not change if it was previously set.
*NONE: No TCP/IP domain name is defined for this system.
character-value: Specify the TCP/IP domain name for this system.

Example of how to use the DMNNAME parameter to specify this system's TCP/IP domain name:

   CHGTCPDMN DMNNAME ('dom1.abc.com')

Domain search list (DMNSCHLIST)

Specify the TCP/IP domains to search when fully-qualified domain names (FQDN) are not given. The first name in the search list is the default domain name on all searches.

*SAME: The domain search list does not change if it was previously set; otherwise *DFT is used.
*DFT: The default behavior is to search the local domain tree. The local domain tree is the system TCP/IP domain name (DMNNAME) and each parent domain with two or more parts to the domain. The system TCP/IP domain name is the default domain name on all searches.
character-value: Specify the list of domain names to be searched. Up to six domain names may be specified, separated by spaces and enclosed in apostrophes. The first domain name in the search list is the default domain name on all searches. Note that if a domain search list is defined then the local system TCP/IP domain name (DMNNAME) will not automatically be used in the search list. Parent domains for the domains defined in the search list will not be searched. If you want parent domains to be searched then they must be explicitly defined in the search list.

Example of how to use the DMNSCHLIST parameter to specify this system's domain search list:

   CHGTCPDMN DMNSCHLIST('dom1.abc.com  dom2.abc.com  abc.com')

Host name search priority (HOSTSCHPTY)

Specifies whether to search a Domain Name Server (DNS) first to resolve a TCP/IP host name conflict, or to search the local TCP/IP host table first.

*SAME: The value does not change if it was previously set. If the value was not previously set, *REMOTE will be used.
*REMOTE: Specify *REMOTE if you want this system to search a remote or local Domain Name Service (DNS) to resolve TCP/IP host names before searching the local TCP/IP host table. The Domain Name Server (DNS) to use is specified by the Internet address (INTNETADR) parameter.
*LOCAL: Specify *LOCAL if you want this system to first search the TCP/IP host table, located on this system, to resolve TCP/IP host names.

Internet address (INTNETADR)

Use this parameter to specify up to three Domain Name Servers (DNS) to be used by this system. Specify a Domain Name Server (DNS) by entering its Internet address. You may add none, one, two, or three Domain Name Server (DNS) Internet addresses.

If the first Domain Name Server (DNS) in the list does not respond, the second DNS server in the list will be contacted. If the second DNS server does not respond, the third DNS server will contacted.

The Domain Name Server (DNS) Internet address must be in decimal form, with a maximum of 15 characters.

This is an example of how to use the INTNETADR parameter to specify a primary and secondary Domain Name Server for use by this system:

   CHGTCPDMN   INTNETADR('9.131.42.251'  '9.131.39.251')

Port (PORT)

Use this parameter to specify the remote TCP/IP port number used to contact the Domain Name Server (DNS) or Servers listed in the INTNETADR parameter. 53 is the well-known port used for this purpose.

Note: Use of a TCP/IP port number other than the well-known port 53 for use by the Domain Name Server (DNS) can result in TCP/IP communication problems. You may inadvertently use a port number which is reserved for use by another TCP/IP application.

*SAME: The remote port number will not be changed if it was previously set. If the remote port number was not previously set, the remote port number 53 will be used.
1-65532r: Specify the remote port number to be used to contact the Domain Name Server (DNS) specified in the INTNETADR parameter.

Protocol (PROTOCOL)

Specify the TCP/IP protocol used to communicate with the Domain Name Server (DNS) specified in the INTNETADR parameter. User Datagram Protocol (UDP) is typically used for this purpose. Use *TCP only if your Domain Name Server (DNS) is specifically configured to use the Transmission Control Protocol (TCP).

*SAME: The protocol value will not be changed if it was previously set. If the protocol value was not previously set, the protocol value *UDP will be used.
*UDP: Specifies use of the User Datagram Protocol (UDP) to communicate with the Domain Name Server (DNS) specified in the INTNETADR parameter.
*TCP: Specifies the use of Transmission Control Protocol (TCP) to communicate with the Domain Name Server (DNS) specified in the INTNETADR parameter.

Initial domain name server (INLDMNSVR)

Specify the initial domain name server selection method. This option determines whether the first configured Domain Name Server (DNS) should always be queried first, or if the first name server to be queried should be rotated in a round robin fashion if more than one is configured. This rotation provides a simple form of load balancing on the configured name servers.

*SAME: The initial domain name server selection value will not be changed if it was previously set. If the initial domain name server selection value was not previously set, the value *FIRST will be used.
*FIRST: The first configured domain name server is queried first. Always query the Domain Name Servers (DNS) in order as configured.
*ROTATE: Rotate through the configured name servers in a round robin fashion to determine which to query first.

Domain name server retry (DMNSVRRTY)

The Domain Name Server Retry (DMNSVRRTY) parameter consists of two elements: number-retries, and time-interval.

The first element; number-retries, specifies the number of additional attempts made to establish communication with each Domain Name Server (DNS) specified in the INTNETADR parameter, in the event that the first attempt fails.

Element 1: Number of retries

*SAME: This is the default value. The number-retries value will not be changed if it was previously set. If the number-retries value was not previously set, the number-retries value of 2 will be used.
1-99: Specify the number of communication retry attempts.

Element 2: Time interval Specifies the length of time in seconds this system will wait before initiating a retry attempt.

*SAME: The time-interval value will not be changed if it was previously set. If the time-interval value was not previously set, the time-interval value of 2 will be used.
1-99: Specify the time-interval in seconds between retry attempts.

Here is an example of how to use the Domain Name Server Retry (DMNSVRRTY) parameter to set the number of retries to three, and the interval between each retry to ten seconds:

   CHGTCPDMN   DMNSVRRTY(3 10)

Examples

Example 1: Change Host and Domain Names

CHGTCPDMN   HOSTNAME(rs021)  DMNNAME(endicott.ibm.com)

This command changes the host name and domain name.

Example 2: Change Domain Search List

CHGTCPDMN   DMNSCHLIST('endicott.ibm.com
                        rochester.ibm.com
                        ibm.com')

This command changes the domain search list to be three domain names: endicott.ibm.com, rochester.ibm.com, and ibm.com.

Example 3: Change Domain Name Server Rotation

CHGTCPDMN   INLDMNSVR(*ROTATE)

This command changes the initial domain name server selection so it rotates between the configured name servers in a round robin fashion.