PowerHA Geographic mirroring automatically selects an open port between 1024 and 65535 on the mirror copy node for receiving data. This port number is selected dynamically every time replication starts, offering flexibility in a geographic mirroring environment to find an available port.

In some environments, due to Quality of Service (QoS), network restrictions, security, or firewall requirements it is necessary to have applications use specific ports for network activity. Geographic mirroring allows the administrator to specify a port that the geographic mirror copy will use for listening and receiving data.

Before you Begin

This functionality requires a PTF to be installed on all nodes in the geographic mirroring environment. The required PTFs for each supported release are:

Restrictions

1. Only a single port number can be specified. This port number will be used as the data port IP address by all nodes in the geographic mirroring environment.

2. This functionality is supported only with clusters containing a single independent auxiliary storage pool (IASP) device in the cluster resource group (CRG). Clusters containing multiple IASP devices have the following additional restrictions:

   1. Each CRG can only have a single IASP device.

   2. Each CRG must use different data port IP addresses.

Procedure

1. Select a port number that the mirror copy will use for listening and receiving data. Here, port 12345 will be used.

2. On every node in the geographic mirroring Cluster Resource Group (CRG), run the following command replacing 12345 with the port selected for the environment:
   ADDSRVTBLE SERVICE(‘geomirror’) PORT(12345) PROTOCOL(‘tcp’)

3. The new port will be used the next time geographic mirroring is resumed. If geographic mirroring is currently active, suspend geographic mirroring and resume geographic mirroring:
   
   

Results

Geographic mirroring will now use the port specified in the service table for geographic mirroring.