[ 1233.573886][T11112] Could not find device with ifindex 2000 in netnsfd 11
[ 1233.574665][T11112] Could not find netns with fd: 2000
[ 1233.575255][T11112] Cannot link a netdevsim to itself
[ 1233.575980][T11112] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).