TCP/IP Communications (Windows Server AppFabric Caching)

All Windows Server AppFabric cache hosts use TCP/IP to communicate with each other and support the cache cluster. To enable this communication, firewall exceptions may be required on the cache hosts. Cache clients use TCP/IP for cache operations, but do not require firewall exceptions to communicate with the cluster.

TCP/IP Port Configuration

To function correctly, each cache server needs firewall exceptions to be configured for the cache service. Four separate ports are used: the cache port, the cluster port, the arbitration port, and the replication port.

The port numbers specified for these ports can be different for each cache host and cache client. The cache cluster keeps track of the ports for all cache hosts in the cluster configuration settings so that cache hosts can maintain communications with each other.


If you use the Windows Firewall, you can choose to automatically create firewall exceptions for these ports with the AppFabric Configuration Wizard.

These four ports are summarized in the following table:

Port Name Default Value Application Configuration File Attribute Cluster Configuration File Attribute

cache port




cluster port


Not applicable


arbitration port


Not applicable


replication port


Not applicable



You can change these port values by using the Set-CacheHostConfig Windows PowerShell command. For more information, see Using Windows PowerShell to Manage Windows Server AppFabric Caching Features.

Cache Port

The cache port is used for transmitting data between the cache hosts and your cache-enabled application. The default is 22233.

Cluster Port

The cache hosts use the cluster port to communicate availability to each of their neighbors in the cluster. The default is 22234.

Arbitration Port

If a cache host fails, the arbitration port is used to make certain that the cache host is unavailable. The default is 22235.

Replication Port

The replication port is used to move data between hosts in the cache cluster. This supports features such as high availability and load balancing. The default is 22236.

Security Considerations

During configuration, you must create firewall exceptions for these ports. If you are using Windows Firewall, you can choose to have this done automatically by the AppFabric Configuration Wizard. After uninstalling the cache service, we recommend that you manually reconfigure these ports based on company security policy and the needs of other applications on the server. In some cases, that may mean closing these ports in the firewall.

See Also


Windows Server AppFabric Caching Physical Architecture Diagram
Windows Server AppFabric Caching Logical Architecture Diagram
Using Windows PowerShell to Manage Windows Server AppFabric Caching Features