[  229.876758] Could not find device with ifindex 2000 in netnsfd 11
[  229.876906] Could not find netns with fd: 2000
[  229.876977] netdevsim netdevsim468 eth0: Cannot link a netdevsim to itself
[  229.877078] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).