[ 1081.006616][T11108] Could not find device with ifindex 2000 in netnsfd 11
[ 1081.007761][T11108] Could not find netns with fd: 2000
[ 1081.008742][T11108] Cannot link a netdevsim to itself
[ 1081.009912][T11108] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).