Windows route selection and "route print -6" vs "netsh interface ipv6 show route"

Question

So I'm using Windows 10 and I need to redirect some IPv6 multicast traffic to a specific interface (a USB-Ethernet adapter to be more specific).

By default all multicast traffic is going to my WiFi connection (verified using WireShark). If I disable the WiFi interface, I can observe the multicast traffic in question going to the USB-Ethernet adapter.

route print -6 gives the following output (only relevant networks shown here):

 Active Routes:
 If Metric Network Destination      Gateway
  1   331  ff00::/8                 On-link
 14   286  ff00::/8                 On-link
 15   257  ff00::/8                 On-link

...and netsh interface ipv6 show route shows the following (only relevant networks shown here):

Publish  Type      Met  Prefix                    Idx  Gateway/Interface Name
-------  --------  ---  ------------------------  ---  ------------------------
No       System    256  ff00::/8                    1  Loopback Pseudo-Interface 1
No       System    256  ff00::/8                   14  Wi-Fi
No       System    256  ff00::/8                   15  ethernet_usb

• The metrics are different in both outputs (netsh output shows 256 for all interfaces and route shows values like 331, 286 and 257). What do each of these values mean?

• Secondly, how do I change the order here so that all traffic for ff00::/8 is routed through interface 15 (ethernet_usb). I would prefer not to delete the route completely from the Wi-Fi interface but changing metric through adapter settings didn't seem to have any effect.

Answer 1

First, the route print -6 command show the route metric

Second, the netsh interface ipv6 show route show gateway metric

And, route metric = interface metric + gateway metric

In addition, you can use the command to see what the interface metric is by netsh interface ip show address.