Alcatel-Lucent 7450 Configuration Manual page 55

1. MPLS populates the user configured LSP weight in TTM. When the global command
2. IGP computes the normalized weight for each prefix tunnel next-hop. The minimum value
3. The normalized weights of route tunnel next-hops are updated in the following cases:
4. The weighted load balancing feature is only applied to a prefix when all the tunnel next-
5. Regular ECMP spraying is also applied if a prefix is resolved in RTM to an ECMP set
6. This feature is not supported in the following contexts:
7450 ESS Router Configuration Guide
weighted-ecmp is enabled, and if one or more LSPs in the ECMP set of a prefix does not
have a weight configured, the regular ECMP spraying for the prefix will be performed.
of the normalized weight is 1 and the maximum if 64. IGP 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.
→ When the main SPF is run following a trigger, e.g., network failure, and updates a
given route with a modified set of tunnel next-hops. This will trigger a route re-
download to the IOM and all users of RTM are notified.
→ The user adds or changes the weight of one or more LSPs. In this case, RTM will
perform a route download to IOM but other users of RTM should not be notified since
the route resolution did not change.
hops in the ECMP set have the same endpoint. If an IGP prefix resolves in RTM to a set of
ECMP tunnel next-hops which do not terminate on the same endpoint, the regular ECMP
spraying is performed. If BGP performs BGP ECMP to a set of BGP ECMP next-hops for
a prefix [weighted-bgp-ecmp-prd], regular ECMP spraying is performed towards a given
BGP next-hop if the subset of its tunnel next-hops does not terminate on the same
endpoint.
which consists of a mix of IP and tunnel next-hops.
→ Packets of BGP prefix with the BGP next-hop resolved in TTM to RSVP LSP (BGP
shortcut).
→ CPM generated packets, including OAM packets, which are looked-up in RTM and
which are forwarded over tunnel next-hops. These will continue to be forwarded using
either regular ECMP or by selecting one next-hop from the set as in existing
implementation.
IP Router Configuration
Page 55