3Com S7906E Configuration Manual page 2578

An 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. As soon as the master fails,
the IRF system elects a new master immediately to prevent service interruption and implement 1:N
backup.
Not only the physical IRF ports of members can be aggregated, but also the physical links between the
IRF system and the upper or lower layer devices can be aggregated, and thus the reliability of the IRF
system is increased through the link backup.
Powerful network expansion capability
By adding member devices, you can increase the number of IRF ports and expand network bandwidth.
As all member devices have their own CPUs, they can process and forward protocol packets
independently, thus improving processing capability of the IRF system.
Application
As shown in Figure 1-1, a master and a slave form an IRF, which is a single logical device to the devices
of the upper layer and lower layer. You can deploy an IRF at the core layer, distribution layer, or access
layer.
Figure 1-1 IRF networking
IP network IP network
Slave
Master
IRF
Equals
IRF cable
1-2