Connection name (CONNAME)

This attribute is the communications connection identifier. It specifies the particular communications links to be used by this channel.

It is optional for server channels, unless the server channel is triggered, in which case it must specify a connection name.

Specify CONNAME as a comma-separated list of names of machines for the stated TRPTYPE. Typically only one machine name is required. We can provide multiple machine names to configure multiple connections with the same properties. The connections are usually tried in the order they are specified in the connection list until a connection is successfully established. The order is modified for clients if the CLNTWGHT attribute is provided. If no connection is successful, the channel attempts the connection again, as determined by the attributes of the channel. With client channels, a connection-list provides an alternative to using queue manager groups to configure multiple connections. With message channels, a connection list is used to configure connections to the alternative addresses of a multi-instance queue manager.

Providing multiple connection names in a list was first supported in IBM WebSphere MQ Version 7.0.1. It changes the syntax of the CONNAME parameter. Earlier clients and queue managers connect using the first connection name in the list, and do not read the rest of the connection names in the list. In order for the earlier clients and queue managers to parse the new syntax, we must specify a port number on the first connection name in the list. Specifying a port number avoids problems when connecting to the channel from a client or queue manager that is running at a level earlier than IBM WebSphere MQ Version 7.0.1.

On Multiplatforms, the TCP/IP connection name parameter of a cluster-receiver channel is optional. If you leave the connection name blank, IBM MQ generates a connection name for you, assuming the default port and using the current IP address of the system. We can override the default port number, but still use the current IP address of the system. For each connection name leave the IP name blank, and provide the port number in parentheses; for example:

(1415)

The generated CONNAME is always in the dotted decimal (IPv4) or hexadecimal (IPv6) form, rather than in the form of an alphanumeric DNS host name. The maximum name length depends on the platform:

• 264 characters.
• 48 characters (see note 1).

If the transport type is TCP

CONNAME is either the host name or the network address of the remote machine (or the local machine for cluster-receiver channels). For example, (ABC.EXAMPLE.COM), (2001:DB8:0:0:0:0:0:0) or (127.0.0.1). It can include the port number, for example (MACHINE(123)).

It can include the IP_name of a dynamic DNS group or a Network Dispatcher input port.

If we use an IPv6 address in a network that only supports IPv4, the connection name is not resolved. In a network which uses both IPv4 and IPv6, the connection name interacts with the local address to determine which IP stack is used. See Local Address (LOCLADDR) for further information.

If the transport type is LU 6.2

If the TPNAME and MODENAME are specified, give the fully-qualified name of the partner LU.

If the TPNAME and MODENAME are blank, give the CPI-C side information object name for the specific platform.

There are two forms in which to specify the value:

• Logical unit name The logical unit information for the queue manager, comprising the logical unit name, TP name, and optional mode name. This name can be specified in one of three forms:

  Form	Example
  luname	IGY12355
  luname/TPname	IGY12345/APING
  luname/TPname/modename	IGY12345/APINGD/#INTER

  For the first form, the TP name and mode name must be specified for the TPNAME and MODENAME attributes; otherwise these attributes must be blank. For client-connection channels, only the first form is allowed.
• Symbolic name

  The symbolic destination name for the logical unit information for the queue manager, as defined in the side information data set. The TPNAME and MODENAME attributes must be blank. Note that, for cluster-receiver channels, the side information is on the other queue managers in the cluster. In this case it can be a name that a channel auto-definition exit can resolve into the appropriate logical unit information for the local queue manager.

The specified or implied LU name can be that of a VTAM generic resources group.

If the transmission protocol is NetBIOS

CONNAME is the NetBIOS name defined on the remote machine.

If the transmission protocol is SPX

CONNAME is an SPX-style address consisting of a 4 byte network address, a 6 byte node address and a 2 byte socket number. Enter these values in hexadecimal, with the network and node addresses separated by a period and the socket number in brackets. For example:

CONNAME('0a0b0c0d.804abcde23a1(5e86)')

If the socket number is omitted, the default IBM MQ SPX socket number is used. The default is X'5E86'.

This attribute is valid for channel types of:

• Sender
• Server
• Requester
• Client connection
• Cluster sender
• Cluster receiver

It is optional for server channels, unless the server channel is triggered, in which case it must specify a connection name.

Note:

1. For name lengths, we can work around the 48 character limit in either of the following ways:
   • Set up your DNS servers so that we use, for example, host name of "myserver" instead of "myserver.location.company.com", ensuring we can use the short host name.
   • Use IP addresses.

2. The definition of transmission protocol is contained in Transport type (TRPTYPE).

Parent topic: Channel attributes in alphabetical order