Connecting Through a Firewall

When a client application is separated from the broker by a firewall, special measures are needed in order to establish a connection. One approach is to use the httpjms or httpsjms connection service, which can “tunnel” through the firewall; see Appendix C, HTTP/HTTPS Support for details. HTTP connections are slower than other connection services, however; a faster alternative is to bypass the Message Queue Port Mapper and explicitly assign a static port address to the desired connection service, and then open that specific port in the firewall. This approach can be used to connect through a firewall using the jms or ssljms connection service (or, in unusual cases, admin or ssladmin).

Table 9-8 Broker Configuration Properties for Static Port Addresses

To Enable Broker Connections Through a Firewall

1. Assign a static port address to the connection service you wish to use.

   To bypass the Port Mapper and assign a static port number directly to a connection service, set the broker configuration property imq.serviceName.protocolType.port, where serviceName is the name of the connection service and protocolType is its protocol type (see Table 9-8). As with all broker configuration properties, you can specify this property either in the broker's instance configuration file or from the command line when starting the broker. For example, to assign port number 10234 to the jms connection service, either include the line

   imq.jms.tcp.port=10234

   in the configuration file or start the broker with the command

   imqbrokerd -name brokerName -Dimq.jms.tcp.port=10234

   where brokerName is the name of the broker to be started.

2. Configure the firewall to allow connections to the port number you assigned to the connection service.

   You must also allow connections through the firewall to Message Queue's Port Mapper port (normally 7676, unless you have reassigned it to some other port). In the example above, for instance, you would need to open the firewall for ports 10234 and 7676.