Add TCP/IP Host Table Entry (ADDTCPHTE)

The Add TCP/IP Host Table Entry (ADDTCPHTE) command adds an internet address and its associated host names along with an optional text description field to the local host table. For each entry, the host table is defined to allow one internet address, up to 4 host names, and a text description field.

See also the following host table commands:

Change TCP/IP Host Table Entry (CHGTCPHTE) command changes one or more host names or the text description field
Merge TCP/IP Host Table (MRGTCPHT) command merges host names, internet addresses, and text comment entries from a physical file member into the local host table. A replace option is also provided that allows the entire local host table to be replaced by the host table entries in a user specified physical file member.
Rename TCP/IP Host Table Entry (RNMTCPHTE) command renames the internet address of a host table entry to another internet address
Remove TCP/IP Host Table Entry (RMVTCPHTE) command removes an entire entry from the local host table.

If an internet address already exists in the host table that matches the internet address specified in the command, an escape message is sent to the user and the duplicate internet address is not added.

If a remote name server is being used by your system for resolving a host name or an internet address, the choice to first search the remote name server or the local host table depends on how the searched-first value was configured on the configuration panel of the remote name server. To change the remote name server or the searched-first value, enter the Configure TCP/IP (CFGTCP) command and select option 12.

The TCP/IP host table is shipped with the loopback entry. This entry has an internet address of 127.0.0.1 and two host names; LOOPBACK and LOCALHOST. The LOOPBACK host name can only be associated with an internet address that has a first-byte value equal to 127.

Restrictions:

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

Related APPC over TCP/IP Information

APPC over TCP/IP (AnyNet) uses the host name to map location names to internet addresses. The host name must be in the form:

location.netid.SNA.IBM.COM

Where location is the remote location the program is opening to, and netid is the network identifier for this connection. SNA.IBM.COM is the qualifier that designates this as the APPC over TCP/IP domain.

Location names support characters that cannot be present in host names (for example: $ (dollar), @ (at sign), and # (number sign)). Therefore, the APPC application can open only to locations that fulfill the TCP/IP host name syntax. This limits location names used for APPC over TCP/IP to the characters A-Z (uppercase and lowercase) and 0-9.

Keyword	Description	Choices	Notes
INTNETADR	Internet address	Character value	Required, Positional 1
HOSTNAME	Host names	Values (up to 4 repetitions): Element list	Required, Positional 2
Element 1: Name	Character value
TEXT	Text 'description'	Character value	Optional

Host names (HOSTNAME)

Specifies the host names corresponding to the internet address. The host name can be either the short form or the full domain version of the name. A common practice is to define one short name that is unique within your local network and to also define the full domain version of the host name that is unique within the internet. Specify from 1 to 4 different host names to be associated with the internet address.

A domain name or a host name can be a text string having 1 to 255 characters. Domain names consist of one or more labels separated by periods. Each label can contain up to 63 characters. The first character of each label must be an alphabetic character or a digit. The last character of each label must be an alphabetic character, a digit, or a period. The following characters are allowed in domain names:

Alphabetical characters A through Z
Digits 0 through 9
Underscore (_)
Minus sign (-)
Period (.). Periods are allowed only when they separate labels of the domain style name or as the last character in the domain name. (Refer to RFC 1034.) A domain name cannot have two consecutive periods.

Note: These characters are part of the Syntactic Character Set (character set number 640). This character set is also commonly referred to as invariant.

Other domain name and host name conventions include the following:

Uppercase and lowercase characters are allowed, but no significance is attached to the case. The host name (HOSTNAME) may be converted to uppercase depending on the combination of characters and digits. If the HOSTNAME is enclosed in apostrophes ('), the case is maintained as entered.
The host name returned when searching the host table for an internet address is the first host name associated with the internet address. For example, if the address 9.130.38.187 is defined in the host table with names ROCHESTER, JOHN, and RCHAS100, the name ROCHESTER would be returned. The other two host names would not be used in this type of search. However, these host names would be used when searching the host table to find the internet address associated with the names JOHN and RCHAS100.
Try to limit your domain name labels to 12 characters. Shorter labels are easier to remember.
It is a common practice to use hierarchical names that allow predictable extensions for change and growth. Domain names normally reflect the delegation of authority or hierarchy used to assign them. For example, the name SYS1.MFG.ABC.COM can be broken down into the following:

COM

All commercial networks.

ABC.COM

All systems in the ABC company's commercial network.

MFG.ABC.COM

All manufacturing systems in the ABC company's commercial network.

SYS1.MFG.ABC.COM

A host named SYS1 in the manufacturing area of the company's commercial network.

The COM designation is one of several domain names used by convention when connecting to the Internet. Some of the other domain names that follow this convention are:

COM

Commercial organizations

EDU

Educational institutions

GOV

Government institutions

MIL

Military groups

NET

Major network support centers

ORG

Organizations other than those listed previously

ARPA

Temporary ARPANET domain

Country or Region Code

Countries or regions other than the USA

name

Specify a host name to be associated with the specified internet address. When running APPC over TCP/IP, name is in the form:

location.netid.SNA.IBM.COM

The default if a host name is not specified is blanks. At least one host name must specified. An IP address cannot be a host name.

Examples

Example 1: Adding a Short Host Name

ADDTCPHTE   INTNETADR('132.28.71.5')  HOSTNAME(AS400ETH)
            TEXT('AS400ETH on Ethernet subnet')

This command associates the host name AS400ETH with the internet address of 132.28.71.5. The text 'AS400ETH on Ethernet subnet' is saved as the descriptive comment for this host table entry.

Example 2: Adding Two Host Names

ADDTCPHTE   INTNETADR('9.5.42.6')
            HOSTNAME((AS400ETH.SALES.ABC.COM)
                     ('as400eth.sales.abc'))
            TEXT('Entry verified on 1 April 1994 by J. Jones')

This command associates the host names AS400ETH.SALES.ABC.COM and AS400ETH.SALES.ABC with the internet address of 9.5.42.6. Because no significance is attached to a case, a match is found on host name AS400ETH.SALES.ABC.COM or as400eth.sales.abc. The text 'Entry verified on 1 April 1994 by J. Jones' is saved as the descriptive comment for this host table entry.