In centos 8(4.18.0-193.28.1.el8_2.x86_64) if I try this command:
ip link add team0:1 type dummy
I will get a message: "RTNETLINK answers: Invalid argument". However if I do the same thing on Centos 7(3.10.0-862.14.4.el7.x86_64), there is no error ! And If I cat /proc/net/dev I can see there is a sub interface:
Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
eth0: 2489766199 690315 0 0 0 0 0 0 96022876 713917 0 0 0 0 0 0
lo: 402582904 916378 0 0 0 0 0 0 402582904 916378 0 0 0 0 0 0
team0:1: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
What is wrong ? Is there a bug in Centos 7? Shouldn't /proc/net/dev show net interfaces only with no sub interfaces?
I couldn't find an answer after doing all the searchings and googlings, to those who has a better understanding on this: please be so kind and help me ~