Free 642-883 Sample Question 8
When configuring IPv4 and IPv6 IS-IS routing on Cisco IOS XR routers, which three statements are correct? (Choose three.)
A. By default, a single SPF is used for both IPv4 and IPv6, so the IPv4 and IPv6 topology should be the same.
B. By default, the IS-IS router type is Level 1 and Level 2.
C. All IS-IS routers within the same IS-IS area must be configured with the same IS-IS routing process instance ID.
D. By default, metric-style narrow is used.
E. By default, the IS-IS interface circuit type is Level 1 and Level 2.
F. The area IS-IS address-family configuration command is used to specify the IS-IS area address
Correct Answer: B,D,E
The default metric style for single topology is narrow metrics. However, you can use either wide metrics or narrow metrics. How to configure them depends upon how single-topology is configured. If both IPv4 and IPv6 are enabled and single-topology is configured, the metric style is configured in the address-family ipv4 stanza. You may configure the metric style in the address-family ipv6 stanza, but it will be ignored in this case. If IPv6 only is enabled and single topology is configured, then the metric style is configured in the address-family ipv6 stanza.