Question

You are an SP engineer running IS-IS with the default narrow metric-style on a core router. You attempt to configure an interface with 'isis metric 100' on Level-2, but you also need to raise several other links to values that reflect a new 10G-versus-1G design. The design team asks you to set one uplink to a metric of 200, but the router rejects the command. Assuming metric-style has NOT been changed, what is the maximum interface metric value IS-IS will accept, and why?

Accepted Answer

63, because narrow metrics use a 6-bit field limiting the per-interface metric to a maximum of 63

Answer

255, because narrow metrics use an 8-bit field limiting the per-interface metric to a maximum of 255

Answer

1023, because narrow metrics use a 10-bit field for interface metrics

Answer

16777215, because IS-IS interface metrics always use the wide 24-bit field