IPv6 Configuration Guide K/KA/KB.15.15

Example 177 show ipv6 route command output with multiple next-hop routes
HP Switch(config)# show ipv6 route
IPv6 Route Entries
Destination : ::1/128
Gateway : lo0
Type: connected Sub-Type: NA Distance: 0 Metric: 1
Destination : 2620:c::/64
Gateway : 2620:e::55:2
Type: static Sub-Type: NA Distance: 200 Metric: 1
Destination : 2620:a::/64
Gateway : fe80::22:3%vlan22
Type: ospf3 Sub-Type: InterArea Distance: 110
1
Metric: 2
Destination : 2620:a::/64
Gateway : fe80::22:5%vlan22
Type: ospf3 Sub-Type: InterArea Distance: 110 Metric: 2
Destination : 2620:a::/64
Gateway : fe80::22:11%vlan22
Type: ospf3 Sub-Type: InterArea Distance: 110 Metric: 2
Destination : 2620:b::/64
Gateway : VLAN22
Type: connected Sub-Type: NA Distance: 0 Metric: 1
1
Multiple next-hop gateway addresses are displayed for the
destination network 2620:a::/64
For a given destination network in an OSPFv3 domain, multiple ECMP next-hop routes can be one
of the following types.
• Intra-area (routes to the destination in the same OSPFv3 area)
• Inter-area (routes to the destination through another OSPFv3 area)
• External (routes to the destination through another autonomous system)
Multiple ECMP next-hop routes cannot be a mixture of intra-area, inter-area, and external routes.
For example, in Example 177 (page 256), the multiple next-hop routes to network 2620:a::/64
are all inter-area.
Also, according to the distributed algorithm used in the selection of ECMP next-hop routes:
• Intra-area routes are preferred to inter-area routes.
• Inter-area routes are preferred to external routes through a neighboring AS.
In addition, ECMP ensures that all traffic forwarded to a given host address follows the same path,
which is selected from the possible next-hop routes.
ECMP load-sharing does not affect routed traffic to different hosts on the same subnet. That is, all
traffic for different hosts on the same subnet will go through the same next-hop router. For example,
if subnet 2001:db8:0:1f::/64 includes two servers at 2001:db8:0:1f::1ab.101 and
2001:db8:0:1f::1ab.93, all traffic from router "A" to these servers will go through the same
next-hop router.
OSPFv3 Activation and Dynamic Configuration
All configuration commands affecting OSPFv3 (except reconfiguring the router ID) are dynamically
implemented and can be used without restarting OSPFv3 routing.
256 OSPFv3 Routing