[    2.352164] ip (243) used greatest stack depth: 12704 bytes left
[    2.551968] Could not find device with ifindex 2000 in netnsfd 11
[    2.552152] Could not find netns with fd: 2000
[    2.552250] Cannot link a netdevsim to itself
[    2.552369] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).