Graphite's plaintext metrics receiver — one metric per line, no authentication at all.
IANA currently registers 2003 as brutus, and older /etc/services files call it cfingerd or GNU finger, but on a modern host this is Graphite: carbon-cache's plaintext line receiver runs on 2003 by default and accepts lines of the form "metric.path value timestamp". Anything that ships metrics — collectd, StatsD backends, Diamond, application code — writes here. If 2003 is open on a monitoring box, it is the metrics firehose inlet.
Do not expose
The plaintext protocol has no authentication and no rate limiting, so anyone who can reach it can poison your metrics or fill the disk with new whisper files — bind it to the private network.
$ printf 'whatport.test 1 %s\n' "$(date +%s)" | nc -w 2 TARGET 2003Seen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
Get Beige Box →also available as JSON · Markdown
Corrections or a missing port? Reply @rimrocksystems.