26-2Figure 27-1 IRF networkingIP networkIRFIP networkIRF cable IRF cableEqualsMaster Slave SlaveIRF has the following advantages:z Simple managementAfter an IRF is formed, you can log in to the IRF system by connecting to a port of any IRF member.When you log in to the IRF, actually you log in to the master device of the IRF. You can manage all IRFmembers by configuring the master, for example, allocating IP addresses to the members,interconnecting the members, and running routing protocols.z Powerful network expansion capabilityBy adding member devices, you can increase the number of IRF ports, expand network bandwidth,and improve processing capability of the IRF system.z High reliabilityNot only the physical IRF ports of members can be aggregated, but also the physical links between theIRF system and the upper or lower layer devices can be aggregated, and thus the reliability of the IRFsystem is increased through the link backup.The IRF system comprises multiple member devices: the master runs, manages and maintains the IRF,whereas the slaves process services as well as functioning as the backups. When the master fails, theIRF system elects a new master immediately to prevent service interruption and implement 1:Nbackup.IRF Working ProcessThe life cycle of an IRF involves four stages: IRF Connections, Topology Collection, Role Election, andIRF Management.IRF ConnectionsPysical IRF portTo make an IRF operate normally, you need to connect the IRF members physically. Physical portsthat are dedicated to IRF connection on devices are called physical IRF ports. For the Switch 4210Gseries, the 10 GE interface modules can be inserted into the expansion module slots on the rear panel
