Reports the hostname (and optional domain name) that originated this syslog message, per RFC 5424, with a zero-length string meaning unknown. Admins use this to identify which device or host actually generated the message, which matters when a syslog collector aggregates messages relayed from many different sources. A message showing syslogMsgHostName of a specific switch's name tells an admin the entry originated from that switch rather than the relaying collector itself.