Aggregate Next Hop; Invalidate Next-Hop Based On Arp/Neighbor Cache State - Alcatel-Lucent 7450 Configuration Manual

Aggregate Next Hop

This feature adds the ability to configure an indirect next-hop for aggregate routes. The
indirect next-hop specifies where packets will be forwarded if they match the aggregate
route but not a more-specific route in the IP forwarding table.

Invalidate Next-Hop Based on ARP/Neighbor Cache State

This feature invalidates next-hop entries for static-routes when the next-hop is no longer
reachable on directly connected interfaces. This invalidation is based on ARP and
Neighbor Cache state information.
When a next-hop is detected as no longer reachable due to ARP/Neighbor Cache expiry,
the route's next-hop is set as unreachable to prevent the SR from sending continuous
ARPs/Neighbor Solicitations triggered by traffic destined for the static-route prefix. When
the next-hop is detected as reachable via ARP or Neighbor Advertisements, the state of the
next-hop is set back to valid.
Invalidate Next-Hop Based on IPV4 ARP
This feature invalidates a static route based on the reachability of the next-hop in the ARP cache
when a specific flag is added to the static route.
static-route {ip-prefix/prefix-length| ip-prefix netmask } next-hop ip-int-name|ip-address
validate-next-hop
In this case, when the ARP entry for the next-hop is INVALID or not populated, the static route
must remain invalid/inactive. When an ARP entry for the next-hop is populated based on a
gratuitous ARP received or periodic traffic destined for it and the normal ARP who-has procedure,
the static route becomes valid/active and is installed.
Invalidate Next-Hop Based on Neighbor Cache State
This feature invalidates a static route based on the reachability of the next-hop in the neighbor
cache when a specific flag is added to the static route.
configure router static-route 2001:db8::/64 next-hop 2001:db8:abba::2 validate-next-hop
In this case, when the Neighbor Cache entry for next-hop is INVALID or not populated, the static
route must remain invalid/inactive. When an NC entry for next-hop is populated based on a
7450 ESS Router Configuration Guide
IP Router Configuration
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