Chapter 2. Networking

Changes to HPN Add-On

Starting with Red Hat Enterprise Linux 6.6, the High Performance Networking (HPN) Add-On is no longer be available as a separate product. Instead, the functionality found in the HPN Add-On has been integrated into the base product and delivered as part of the Red Hat Enterprise Linux base channel.
In addition to including the HPN functionality into the base Red Hat Enterprise Linux 6 product, the RDMA over Converged Ethernet (RoCE) implementation has also been updated. RoCE uses Global Identifier or GID-based addressing for node-to-node communication. Previously, GIDs were encoded based on the Ethernet interface's MAC address along with the VLAN ID (if used). Under certain circumstances, the compute entity that runs the RoCE protocol is not aware that its traffic is VLAN-tagged. The compute entity can then sometimes create or assume a wrong GID, which can result in connectivity problems. The updated RoCE implementation resolves this problem by changing the way the RoCE GIDs are encoded, and instead bases them off the IP addresses of the Ethernet interface. All systems that use the RoCE protocol need to be upgraded to Red Hat Enterprise Linux 6.6 to ensure connection reliability due to this change in the wire protocol format.
Please refer to this Red Hat Knowledge Base article for additional information: https://access.redhat.com/site/articles/971333.