From: William Tu
Date: Fri, 18 May 2018 19:22:28 -0700
> Currently ip6gre and ip6erspan share single metadata mode device,
> using 'collect_md_tun'. Thus, when doing:
> ip link add dev ip6gre11 type ip6gretap external
> ip link add dev ip6erspan12 type ip6erspan external
> RTNETLINK answer
Currently ip6gre and ip6erspan share single metadata mode device,
using 'collect_md_tun'. Thus, when doing:
ip link add dev ip6gre11 type ip6gretap external
ip link add dev ip6erspan12 type ip6erspan external
RTNETLINK answers: File exists
simply fails due to the 2nd tries to create the same
