[ 1231.076607][T11134] Could not find device with ifindex 2000 in netnsfd 11
[ 1231.077404][T11134] Could not find netns with fd: 2000
[ 1231.077978][T11134] Cannot link a netdevsim to itself
[ 1231.078736][T11134] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).