It seems like the "Ip Address Range" in the "Discovery Settings" does not limit the discovery to the specified range, if a router, which is being discovered, has IP addresses on the interfaces that are not reachable for the LMS, the LMS still tries to ping them, even though those IPs are outside of the scope of the specified range. It also tries to ping the IP addresses configured in the static NAT statements on that router (?). The allowed range is specified as 10.[224-227].*.*
Maybe this is a designed behavior?