To determine the interface index (IfIndex), you can calculate it, or use the CLI command provided in this section.
As a result of channelization support, the IfIndex of each channelization–capable port increases by 4. The number is reserved for the 3 sub-ports when channelization is enabled.
For switches that include channelization-capable ports, use the following equations to determine the IfIndex of a port:
If the port does not support channelization, use (64 x slot number) +128 + (port number -1).
If the port supports channelization, use the following equations:
for the port in question: (64 x slot number) +128
for subsequent ports: (64 x slot number) +128 + ((port number -1) *4)
This equation reserves space for the creation of the 3 sub-ports on the previous port, if or when you enable channelization.
The slot number is 1 for the 5320 Series, 5420 Series, 7520 Series, and 7720 Series.
The slot numbers are 1-2 for the 5520 Series and 5720 Series.
To determine the port interface index through the CLI, use the following command:
show interfaces gigabitEthernet
The following example shows output for this command:
Switch:1(config)#show interfaces gigabitEthernet
==========================================================================================
Port Interface
==========================================================================================
PORT LINK PORT PHYSICAL STATUS
NUM INDEX DESCRIPTION TRAP LOCK MTU ADDRESS ADMIN OPERATE
------------------------------------------------------------------------------------------
1/1 192 1000BaseTX true false 1950 f0:64:26:70:f8:00 up up
1/2 193 1000BaseTX true false 1950 f0:64:26:70:f8:01 up down
1/3 194 1000BaseTX true false 1950 f0:64:26:70:f8:02 up down
1/4 195 1000BaseTX true false 1950 f0:64:26:70:f8:03 up down
1/5 196 1000BaseTX true false 1950 f0:64:26:70:f8:04 up down
1/6 197 1000BaseTX true false 1950 f0:64:26:70:f8:05 up down
1/7 198 1000BaseTX true false 1950 f0:64:26:70:f8:06 up down
1/8 199 1000BaseTX true false 1950 f0:64:26:70:f8:07 up down
1/9 200 1000BaseTX true false 1950 f0:64:26:70:f8:08 up down
1/10 201 1000BaseTX true false 1950 f0:64:26:70:f8:09 up down
1/11 202 1000BaseTX true false 1950 f0:64:26:70:f8:0a up down
1/12 203 1000BaseTX true false 1950 f0:64:26:70:f8:0b up down
1/13 204 1000BaseTX true false 1950 f0:64:26:70:f8:0c up down
--More-- (q = quit)