[  230.901617] Could not find device with ifindex 2000 in netnsfd 11
[  230.901728] Could not find netns with fd: 2000
[  230.901790] netdevsim netdevsim310 eth0: Cannot link a netdevsim to itself
[  230.901875] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).