ipv6 metric-delay advertisement enable

Usage Scenario

Traditional path computation algorithms compute the optimal path to a destination address based on costs. However, such a computed path may not have the minimum delay. For services that have stringent requirements on delay, path computation can be performed based on delay instead of costs to ensure that service traffic is transmitted along the path with the minimum delay. To meet these requirements, run the ipv6 metric-delay advertisement enable command to enable the advertisement of IPv6 delay information for an IS-IS process. After this function is enabled, IS-IS collects and floods information about the intra-area IPv6 link delay, and BGP-LS reports the information to the controller. This allows the controller to use the delay information to compute the optimal path on the P2P network. Delays in controlled include dynamic monitoring delay and static configuration delay.

Prerequisites

The cost type for the IS-IS routes that a device can send and accept has been set to wide, wide-compatible, or compatible using the cost-style command. In addition, the IPv6 capability for an IS-IS process has been enabled using the ipv6 enable command, IPv6 TE has been enabled for an IS-IS process using the ipv6 traffic-eng command.

Precautions

The published delay can be a dynamic delay measured by TWAMP light or a configured static delay.

For dynamic delay, an IS-IS interface bound to a TWAMP Light session, delay information can be advertised to this interface only when the TWAMP Light session detects valid statistics. Upon receipt, IS-IS advertises and floods the delay information.

In scenarios where the IPv6 capability is enabled for an IS-IS process and the network topology type is set to standard, if the function to advertise IPv4 delay information is enabled and TWAMP has detected IPv4 delay data, IS-IS floods the IPv4 delay data on the entire network. If no IPv4 delay data is detected or the function to advertise IPv4 delay information is disabled but the function to advertise IPv6 delay information is enabled and TWAMP has detected IPv6 delay data, IS-IS floods the IPv6 delay data on the entire network.

If the IPv6 capability is enabled for an IS-IS process and the network topology type is set to IPv6, IS-IS floods the IPv6 delay information on the entire network.

In scenarios where the IPv6 capability is enabled for an IS-IS process and the network topology type is set to compatible, if the function to advertise IPv4 delay information is enabled and TWAMP has detected IPv4 delay data, IS-IS floods the IPv4 delay data in topology 0 on the entire network. If no IPv4 delay data is detected or the function to advertise IPv4 delay information is disabled but the function to advertise IPv6 delay information is enabled and TWAMP has detected IPv6 delay data, IS-IS floods the IPv6 delay data in topology 2 on the entire network.