Different default metric for IPv6 routes when ip and route commands are used

Issue

If a IPv6 route is specified without any metric the value for it is different using ip command and route command.

Let's try to setup a default GW as en example below:

Using route command from net-tools rpm package the default metric is 1

# ip -6 r show | grep default

# route add -A inet6 default gw XXXX:YYYY::ZZZ dev ethX

# ip -6 r show  | grep default
default via XXXX:YYYY::ZZZ dev ethX metric 1 

Using ip command from iproute2 rpm package the default metric is 1024

# ip -6 r show  | grep default

# ip -6 route add default via XXXX:YYYY::ZZZ dev ethX

# ip -6 r show  | grep default
default via XXXX:YYYY::ZZZ dev ethX metric 1024 

Why the metric is not the same in both cases?