| Exam 642-883 | Question id=3425 | IS-IS, IPv4, and IPv6 in Service Provider Environments |
When configuring IPv4 and IPv6 IS-IS routing on Cisco IOS XR routers, which three statements are correct?
| 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. |
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.