1-6 
addition, you can only bind IRF-port 1 to physical stack ports 1 and 2, and IRF-port 2 to physical ports 3 
and 4. 
 
 
If one dual-port interface module and one single-port interface module are installed, you can bind two 
physical stack ports on the dual-port interface module to the logical stack port in aggregate mode, and 
bind the physical stack port on the single-port interface module to the other logical stack port in 
non-aggregate mode. In this situation, IRF-port 2 or IRF-port 1 can be bound to any physical port on the 
device, because only one logical stack port is needed on Switch B or Switch C. 
 
Application and Advantages 
Typically, you can use an IRF stack in the distribution layer; and you can also apply it in the access layer. 
An IRF stack is a single logical device to the users and devices of the upper layer and lower layer, as 
shown in 
Figure 1-7. 
Figure 1-7 IRF stack networking 
IP network
IRF stack
IP network
Stack 
cable
Stack 
cable
Equals
Master
Slave
Slave
 
 
IRF stack has the following advantages: 
z  Simple management 
After an IRF stack is formed, you can log in to the IRF stack system by connecting to a port of any stack 
member. When you log in to the stack, actually you log in to the master device of the stack. You can 
manage all stack members by configuring the master, for example, allocating IP addresses to the 
members, interconnecting the members, and running routing protocols. 
z  Powerful network expansion capability 
By adding member devices, you can increase the number of stack ports, expand network bandwidth, 
and improve processing capability of the stack system. 
z  High reliability