___  _____  ____  ____  _  _  _____  ____  ____
  / __)(  _  )(  _ \( ___)( \/ )(  _  )(_  _)(  _ \ 
 ( (__  )(_)(  )(_) ))__)  \  /  )(_)(  _)(_  )(_) )
  \___)(_____)(____/(____)  \/  (_____)(____)(____/
   PASTEBIN - CREATED: 2019/07/10 at 20:05 (CEST)

your paste:
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iface eth0:0 inet6 static
    address 2a01:4f8:c2c:1fd2::1/64
    gateway fe80::1
    post-up route add -A inet6 default gw fe80::1%eth0 || true
    pre-down route del -A inet6 default gw fe80::1%eth0 || true

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                                                    thanks for using me.