server.go
func (s *Server) SetIPBlockList(list iplist.Ranger) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.ipBlockList = list
}
func (s *Server) SetIPBlockList(list iplist.Ranger) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.ipBlockList = list
}
// Packets to and from any address matching a range in the list are dropped.