First you should check, whether and which IPv6 addresses are already configured (perhaps auto-magically during auto-configuration).
Usage:
# /sbin/ip -6 route show [dev <device>]
Example:
# /sbin/ip -6 route show dev eth0 2001:0db8:0:f101::/64 proto kernel metric 256 mtu 1500 advmss 1440 fe80::/10 proto kernel metric 256 mtu 1500 advmss 1440 ff00::/8 proto kernel metric 256 mtu 1500 advmss 1440 default proto kernel metric 256 mtu 1500 advmss 1440
Usage:
# /sbin/route -A inet6
Example (output is filtered for interface eth0). Here you see different IPv6 routes for different addresses on a single interface.
# /sbin/route -A inet6 |grep -w "eth0" 2001:0db8:0:f101 ::/64 :: UA 256 0 0 eth0 <- Interface route for global ¬ address fe80::/10 :: UA 256 0 0 eth0 <- Interface route for link-local ¬ address ff00::/8 :: UA 256 0 0 eth0 <- Interface route for all multicast ¬ addresses ::/0 :: UDA 256 0 0 eth0 <- Automatic default route