CommCell Components Not Communicating through VPN

Components making up a CommCell instance are not communicating with each other using HTTP encapsulation through a VPN tunnel, despite all the network components being configured correctly.

Symptoms

All the network devices between two components of a CommCell group are configured correctly, and the packet stream is flowing, but the receiving component cannot read the stream.

Causes

CommCell components normally communicate with each other by encapsulating the data stream in HTTP and/or HTTPS. When some third-party network equipment sees HTTP, it adds or otherwise modifies our headers, filters the packets, or injects additional packets into our stream. While this is typically done for security reasons, it causes communication to fail because the receiving-end software is not seeing what it expects.

Resolution

Bypass HTTP encapsulation by setting the Tunnel Connection Protocol to **Raw**. The network equipment then passes the unencapsulated traffic as-is. See [Configuring Tunnel Connection Protocols](http://documentation.commvault.com/commvault/v10/article?p=features/firewall/firewall_new_how_to.htm#Configuring_Tunnel_Connection_Protocols) for more information and the procedure.