Looks like this is libvirt bug, because same behavior on fedora 34 with libvirt 7.0.0-8, but works correct on fedora 35 with 7.6.0-5
Fedora 34: [root@fedora ~]# ip link 5: test: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000 link/ether 52:54:00:45:0b:ac brd ff:ff:ff:ff:ff:ff Fedora 35: [root@f35 ~]# ip link 5: test: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 9000 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000 link/ether 52:54:00:c8:0e:c0 brd ff:ff:ff:ff:ff:ff
