The monitor name requirements and implications are tricky and I do not fully understand them. Although arbitrary names can be used, there are some situations where an attempt to resolve these names is made and a failure to do so will result in a subtly different behavior. My own rule ( I don't know if it's a sane rule ;-) is to always use hostnames without the domain name and always make sure these hostname resolve properly. For instance on bm0101.the.re the monitor will be named bm0101 and getent hosts bm0101 will resolve to the same IP as bm0101.the.re.