The Mesos agent port in modern clusters; registered to Symantec's Intruder Alert agent.
IANA registers 5051 as ita-agent, the agent side of Symantec's Intruder Alert host intrusion detection product, which is long discontinued. What you find on 5051 today is normally an Apache Mesos agent, whose default --port is 5051 while the master uses 5050. The agent exposes HTTP endpoints describing the tasks and executors running on that host.
Do not expose
A Mesos agent endpoint reveals what is running on the node and is part of the cluster control path; keep it on the internal network alongside the master.
$ curl -s http://TARGET:5051/state | head -c 400Seen 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.