[ 1231.357596][T11112] Could not find device with ifindex 2000 in netnsfd 11
[ 1231.358293][T11112] Could not find netns with fd: 2000
[ 1231.358854][T11112] Cannot link a netdevsim to itself
[ 1231.359536][T11112] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).