Simple Network Management Protocol | 1003Deriving Interface IndicesFTOS assigns an interface number to each (configured or unconfigured) physical and logical interface.Display the interface index number using the command show interface from EXEC Privilege mode, asshown in Figure 48-25.Figure 48-25. Display the Interface Index NumberThe interface index is a binary number with bits that indicate the slot number, port number, interface type,and card type of the interface. FTOS converts this binary index number to decimal, and displays it in theoutput of the show interface command.Figure 48-26. Interface Index Binary CalculationsStarting from the least significant bit (LSB):• the first 14 bits represent the card type• the next 4 bits represent the interface type• the next 7 bits represent the port number• the next 5 bits represent the slot number• the next 1 bit is 0 for a physical interface and 1 for a logical interface• the next 1 bit is unusedFor example, the index 72925242 is 100010110001100000000111010 in binary. The binary interface indexfor GigabitEthernet 1/21 of a 48-port 10/100/1000Base-T line card with RJ-45 interface is shown inFigure 48-27. Notice that the physical/logical bit and the final, unused bit are not given. The interface isphysical, so this must be represented by a 0 bit, and the unused bit is always 0. These two bits are not givenbecause they are the most significant bits, and leading zeros are often omitted.FTOS#show interface gig 1/21GigabitEthernet 1/21 is up, line protocol is upHardware is Force10Eth, address is 00:01:e8:0d:b7:4eCurrent address is 00:01:e8:0d:b7:4eInterface index is 72925242[output omitted]FTOS#show linecard all | grep 11 online online E48TF E48TF 7.7.1.1 48Card TypeInterface TypePort NumberSlot Number14 bits4 bits7 bits1 bitUnused5 bits1 bitP/L Flag
