[ 1222.979479][T11127] Could not find device with ifindex 2000 in netnsfd 11
[ 1222.980254][T11127] Could not find netns with fd: 2000
[ 1222.980859][T11127] Cannot link a netdevsim to itself
[ 1222.981613][T11127] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).