anchor.diff:      client.wait_until_succeeds("ping -6 -c 1 FD42::1")
   
       # the global IP of the ISP router should still not be a reachable
  -    router.fail("ping -6 -c 1 2001:DB8::")
  +    router.fail("ping -6 -c 1 2001:DB8::1")
   
       # Once we have internal connectivity boot up the ISP
       isp.start()
  
positive.code:         firewall.enable = false;
          interfaces.eth1.ipv4.addresses = lib.mkForce []; # no need for legacy IP
          interfaces.eth1.ipv6.addresses = lib.mkForce [
            { address = "2001:DB8::"; prefixLength = 64; }
          ];
        };
  
  
negative.code: 
      # wait until the uplink interface has a good status
      router.wait_for_unit("network-online.target")
      router.wait_until_succeeds("ping -6 -c1 2001:DB8::1")
  
      # shortly after that the client should have received it's global IPv6
      # address and thus be able to ping the ISP
      client.wait_until_succeeds("ping -6 -c1 2001:DB8::1")
  
      # verify that we got a globally scoped address in eth1 from the
      # documentation prefix
  