A distributed network monitoring system includes a central monitoring device configured to store global configuration information for all monitoring devices which make up the distributed system, and one or more remote monitoring devices configured to receive, in response to a request therefor, at least a portion of the configuration information from the central monitoring device. Preferred magnetorheological fluids of the present invention comprises polarizable iron particles, a carrier fluid, and optionally an additive. The belt buckle is mounted on another end of the band and has a frame and a buckling element. The AC signal has components at the two frequencies. The message server creates the message by retrieving the message template specified by the identifier and filling in variables in the text in the template with the appropriate personalization tags.