The behavior of this feature in terms of RTM and IOM is exactly the same as in the case of BGP, IGP, and static route prefixes resolving to IGP shortcuts. See Feature behavior for more information. In this case, the static route module computes the normalized weight for each prefix tunnel next-hop of the static route indirect next-hop. The minimum value of the normalized weight is 1 and the maximum is 64. The static route module updates the route in RTM with the set of tunnel next-hops and normalized weights. RTM downloads the information to IOM for inclusion in the FIB.
If any LSP in the ECMP set of a prefix static route does not have a weight configured, the regular ECMP spraying for the prefix is performed.
ECMP is also supported when resolving in TTM the same static route with multiple user-entered indirect next-hops, each binding to the same or different tunnel types. The system picks as many tunnel next-hops as available in RTM, beginning from the first indirect next-hop and up to the value of the ecmp option in the system. In this case, the weighted load-balancing is applied directly using the weights of the selected set of tunnel next-hops. If any LSP in the ECMP set of a prefix static route does not have a weight configured, or if any of the indirect next-hops binds to an LDP LSP, the regular ECMP spraying for the prefix is performed.
If the same prefix is resolved via both a static route and an IGP shortcut route, the RTM default protocol preference installs the static route only. Therefore, the set of ECMP tunnel next-hops and the weighted load balancing behavior are determined by the static route configuration and not by the IGP shortcut configuration.