Why are interface names not named after natural numbers

[Donlon]

Hi,

I have installed the SONiC OS on my Mellanox SN2010 switch, but the naming of the interfaces seems odd. The number of interface names is incremented by four. However the interface names in the Onyx OS and printed in the front panel are both in consecutive natural numbers (Eth 1/1, Eth 1/2, ...). The switch has 18 25GE ports and four 100GE ports, but only the 100GE ports can be split into multiple ports. So I'm curious why are other 25GE ports not named after nature numbers?

Output of command show interfaces status which shows the naming of interfaces:

admin@sonic:~$ show interfaces status
Interface Lanes Speed ...
----------- ----------- ------- ...
Ethernet0 0 25G ...
Ethernet4 4 25G ...
Ethernet8 8 25G ...
Ethernet12 12 25G ...
Ethernet16 16 25G ...
Ethernet20 20 25G ...
Ethernet24 24 25G ...
Ethernet28 28 25G ...
Ethernet32 32 25G ...
Ethernet36 36 25G ...
Ethernet40 40 25G ...
Ethernet44 44 25G ...
Ethernet48 48 25G ...
Ethernet52 52 25G ...
Ethernet56 56 25G ...
Ethernet60 60 25G ...
Ethernet64 64 25G ...
Ethernet68 68 25G ...
Ethernet72 72,73,74,75 100G ...
Ethernet76 76,77,78,79 100G ...
Ethernet80 80,81,82,83 100G ...
Ethernet84 84,85,86,87 100G ...

System version:

SONiC Software Version: SONiC.master.239158-20f1ab820
Distribution: Debian 11.6
Kernel: 5.10.0-18-2-amd64
Build commit: 20f1ab820
Build date: Thu Mar 23 12:56:51 UTC 2023
Built by: AzDevOps@vmss-soni000QAV