...
v7 keeps multiple gateway objects per address, one for each combination of scope and gateway - check.
Changing When target-scope or gateway - check of a route in is changed, ROS v7 will not affect other routes, as it does in v6. In v7 target-scope and gateway - check are properties that are internally attached to the gateway, not to the route.
Gateway check can be extended by setting check-gateway parameter. Gateway reachability can be checked by sending ARP probes, or ICMP messages or by checking active BFD sessions.
Route Storage
Routing information is stored to take as little memory as possible in a common case. These optimizations have non-obvious worst - cases and impact on performance.
...