yes, default is 10
The Integrated IS-IS Global Default Metric feature allows you to use one command to change the metric value globally for all IS-IS interfaces. Besides offering the user the convenience of being able to globally configure the value for all IS-IS interfaces, the feature helps prevent errors that occur when interfaces are individually configured to change the metric value: user can remove metrics from an interface and then add the interface back into IS-IS without a set metric, thereby allowing the default metric 10—unintentionally making that interface a highly preferred one in the network. Such an occurrence on the wrong interface could mean the rerouting of traffic across the network on an undesirable path.
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t4/feature/guide/gtisglob.html#wp1027177
HTH
