If some ipv6 IS-IS routes are not preferred, configure conditions to filter ipv6 IS-IS routes. Only ipv6 IS-IS routes meeting the specified conditions can be added to an IPv6 routing table.
Only routes in an IPv6 routing table can be used to forward IPv6 packets. An IS-IS route can take effect only after this ipv6 IS-IS route has been successfully added to an IPv6 routing table.
If an ipv6 IS-IS route does not need to be added to a routing table, specify conditions, such as a basic ACL6, IPv6 prefix, and routing policy, to filter routes so that only ipv6 IS-IS routes that meet the specified conditions can add to an IPv6 routing table. ipv6 IS-IS routes that do not meet the specified conditions cannot be added to the IPv6 routing table and cannot be selected to forward IPv6 packets.
isis [ process-id ]
ipv6 filter-policy { acl6-number | ipv6-prefix ipv6-prefix-name | route-policy route-policy-name } import