The router id allows to assign origin-based pref-src.

A use case is, when installing default routes originated by two edge routers with different subnets, and the client has 2 ips matching the separate subnets

install ip 0.0.0.0/0                  eq 0    id 00:02:00:00:00:00:1d:01      pref-src 66.199.5.163
install ip 0.0.0.0/0                  eq 0    id 00:02:00:00:00:00:1d:00      pref-src 12.144.66.186

When two similar routes with pref-src were switched, the pref-src was not updated to the new one.
With this fix, switch_routes passes the new->src to change_route, which is used to reapply the install_filter and retrieve the newpref_src from the filter_result.
kernel_route for netlink has been updated to support the newpref_src on ROUTE_MODIFY

It allows to change the metric of an existing redistribute filter using the live config

Allows to send an update of a redistribute metric changed to INFINITY
It adds a command check_xroutes that does not ignore the INFINITY metric of kernel routes