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.
Explanation:
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.
