[  229.737904] Could not find device with ifindex 2000 in netnsfd 11
[  229.738022] Could not find netns with fd: 2000
[  229.738084] netdevsim netdevsim336 eth0: Cannot link a netdevsim to itself
[  229.738169] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).