Use this procedure to enable IPv6 alternative routes and view the configuration on the switch.
enable
configure terminal
Optional: router vrf WORD<1-16>
ipv6 alternative-route

Note
IPv6 alternative routes are enabled by default.
show ipv6 global [vrf WORD<1–16> | vrfids WORD<0–512>]
show ipv6 route alternative [vrf WORD<1–16> | vrfids WORD<0–512>]
Switch:1>enable Switch:1#configure terminal Switch:1(config)#router vrf globalRouter Switch:1(router-vrf)#ipv6 alternative-route
Switch:1#show ipv6 global
================================================================================
                     IPv6 Global Information - GlobalRouter
================================================================================
        forwarding                     : enable
        default-hop-cnt                : 64
        number-of-interfaces           : 0
        icmp-error-interval            : 1000
        icmp-error-quota               : 50
        icmp-unreach-msg               : disable
        icmp-addr-unreach-msg          : enable
        icmp-port-unreach-msg          : enable
        icmp-echo-multicast-request    : enable
        icmp-drop-fragments            : disable
        static-route-admin-status      : enable
        alternative-route              : enable
        ecmp                           : disable
        ecmp-max-path                  : 1
        source-route                   : disable
        host-autoconfig                : disable
                        Switch:1#show ipv6 route alternative
========================================================================================================================
                             IPv6 Routing Table Information - GlobalRouter
========================================================================================================================
Destination Address/PrefixLen  NEXT HOP                         NH VRF/ISID   VID/BID/TID  PROTO   COST  AGE   TYPE PREF
------------------------------------------------------------------------------------------------------------------------
2910:0:0:1:0:0:0:0/64          39-4900-24XE                                     V-3          OSPF    2     0     B    20
2912:0:0:1:0:0:0:0/64          41-VSP8200                                       V-1001       LOCAL   1     0     B    0
2912:0:0:1:0:0:0:0/64          42-VSP-8404                                      T-10         BGP     1     0     A    45
3000:0:0:1:0:0:0:0/64          VSP-8404                                         V-3          LOCAL   1     0     B    0
4001:0:0:1:0:0:0:0/64          45-VSP7400-32                                    T-10         LOCAL   1     0     B    0
5910:0:0:1:0:0:0:0/64          46-VSP8404C                                      T-10         BGP     1     0     B    45
5910:0:0:1:0:0:0:0/64          49-VSP4K                                         V-3          OSPF    2     0     A    120
5910:0:0:2:0:0:0:0/64          219-5420-48P                                     T-10         BGP     1     0     B    45
5910:0:0:2:0:0:0:0/64          223-5420F-24P                                    V-3          OSPF    2     0     A    120
------------------------------------------------------------------------------------------------------------------------
13 out of 13 Total Num of Route Entries displayed.
------------------------------------------------------------------------------------------------------------------------
TYPE Legend:
A=Alternative Route, B=Best Route, E=Ecmp Route