Chapter 8. Global Addressing

The Previous Chapter

The previous chapter defined the LID addresses that are used to route a packet from its source port to its destination port within an IBA subnet. It defined how ports on CAs, switches, and routers are numbered. It then defined the Local ID (LID) address space, the purpose of the LID address, and the SM's assignment of a unique LID to each port. The SM may optionally assign a range of LID addresses to a port. This chapter defined how this is done as well as the value of assigning more than one address to a port. It described how the QP indicates which of the local port's assigned LID addresses will be inserted into the LRH:SLID field when the QP sources a packet to the port for transmission. The concept of the SM's path database was introduced.

This Chapter

This chapter describes the 128-bit global address used to route a packet from its source CA port in one subnet to the destination CA port in another subnet. IPv6 (Internet Protocol version 6) addresses are introduced (both unicast and multicast) as well as the documentation convention used for IPv6 addresses. Each 128-bit global address consists of a 64-bit subnet prefix and a 64-bit globally unique ID (GUID). This chapter describes how each port in a subnet is assigned the same subnet ID as well as one or more GUIDs. The concept of global multi-pathing is introduced.

The Next Chapter

The next chapter introduces the Subnet Manager (SM), the Subnet Management Agent (SMA), the General Services Managers (GSMs), the General Services Agents (GSAs), the Subnet Administrator (SA), the Subnet Management Interface (SMI), the General Services Interface (GSI), Subnet Management Packets (SMPs), and General Services Management Packets (GMPs). The possibility of multiple SMs in one subnet is introduced, along with the concept of GMP redirection, how a trap can deliver an event notification to a manager, and how an entity can subscribe to a manager for the forwarding of event notifications.