HP Integrity rx2800 HP Integrity Network Adapter Teaming Whitepaper - Page 37

Table 4-2 802.1Q Tagged Heartbeat Frame Format (continued) Source MAC address 802.1Q/p tag Length DSAP SSAP SNAP type Data FCS "MAC address of Teamed port" "Value of VLAN ID and Priority" 66 0xAA 0xAA Unnumbered, TEST "Teaming Proprietary data" "Varies" 6 bytes 4 bytes 2 bytes 1 byte 1 byte 1 byte 63 bytes 4 bytes Advanced Redundancy Mechanisms Active Path Active Path is a mechanism used by HP Integrity Network Adapter Teaming to intelligently and proactively determine which teamed ports should or should not be used by the team based on "tested" connectivity with an external network device called an Echo Node. Each teamed port tests connectivity to the Echo Node by transmitting a frame to the Echo Node and monitoring for a response. Active Path can determine if teamed ports have become segregated onto different networks (for example, because of link loss on an upstream switch uplink, server network adapter ports connected to the wrong switch ports, VLAN misconfiguration on a switch, etc.). Teamed port segregation is determined based on successful communication with the Echo Node on a per teamed port basis. Active Path's goals: • To determine if the teamed ports have become segregated into different broadcast domains (in other words, teamed ports pass or fail the connectivity test with the Echo Node) • To only use teamed ports with validated connectivity to the Echo Node for server data communication Active Path is considered an "active" mechanism because it actively transmits and receives a specific type of frame between teamed ports and an external network device called the Echo Node. Active Path uses the results of its connectivity tests to intelligently make decisions to meet the goals above. As discussed earlier, the basic redundancy mechanisms used by HP Integrity Network Adapter Teaming are as follows: • Link loss detection - "Do I have physical link?" • Transmit path validation heartbeats - "Can I successfully transmit a frame onto the network?" • Receive path validation heartbeats - "Can I successfully receive any kind of frame from the network?" These basic mechanisms do not provide for redundancy beyond the network adapter port in the team. In other words, these basic redundancy mechanisms have no ability to detect network conditions that would prevent a particular team member port from being used by the team. If one teamed port is isolated from the rest of the team on another network, the isolated teamed port would most likely pass all three of the basic redundancy mechanisms tests: a) it would have link, b) it could successfully transmit heartbeat frame (it doesn't care if another team member receives it or not), and c) it could receive any kind of broadcast frame that may be transmitted on the isolated segment (from another network device). As a result, the basic redundancy mechanisms don't provide for intelligently choosing which teamed ports to use or not to use. For example, refer to the diagram of an NFT team in Figure 4-4. The HP Integrity server's Primary team member port is connected to Switch A. Switch A's uplink to the Core Switch has been Types of HP Integrity Network Adapter Teams 37