Dell PowerEdge FN I/O Module Configuration Guide 9.10(0.0)

The interface index is a binary number with bits that indicate the slot number, port number, interface type, and card type of the interface. The Dell Networking OS converts this binary index number to decimal, and displays it in the output of the show interface command.

For example, the index 44634369 is 10101010010001000100000001 in binary. The binary interface index for TenGigabitEthernet 0/4 of an Aggregator. Notice that the physical/logical bit and the final, unused bit are not given. The interface is physical, so this must be represented by a 0 bit, and the unused bit is always 0. These two bits are not given because they are the most significant bits, and leading zeros are often omitted.

For interface indexing, slot and port numbering begins with binary one. If the Dell Networking system begins slot and port numbering from 0, binary 1 represents slot and port 0. In the Aggregator the first interface is 0/1 and 0/0s Ifindex is unused and Ifindex creation logic is not changed. Because Zero is reserved for logical interfaces, it starts from 1. For the first interface, port number is set to 1. Adding it causes an increment by 1 for the next interfaces, so it only starts from 2. Therefore, the port number is set to 4 for 0/3.

Dell#show interface tengig 0/2
                                 TenGigabitEthernet 0/2 is up, line protocol is up
                                 Hardware is Dell Force10Eth, address is 00:01:e8:0d:b7:4e
                                 Current address is 00:01:e8:0d:b7:4e
                                 Interface index is 72925242
                                 [output omitted]