- Close the port if nothing on the host needs it.
- Identify the process that listens on it (commands below) before opening it in a firewall.
- Expose a service only to the networks that use it.
Port 151: HEMS
Port 151 is assigned by IANA to hems (HEMS).
How hems works
Other servicesThe client sends a request to port 151 and the hems service answers.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Well-known (0-1023)
- Category
- Other services
Is port 151 dangerous?
We have no specific security note for port 151. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 151
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| hems | 151 | TCP, UDP | HEMS | - | - |
// source: IANA service name and port number registry
Which program uses port 151, and is it reachable?
Linux
sudo ss -ltnup 'sport = :151' # process listening on 151
sudo lsof -nP -i :151macOS
sudo lsof -nP -i :151
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 151 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 151 netstat -ano | findstr :151
From another machine
nmap -p 151 -sV <host> sudo nmap -sU -p 151 <host> nc -zv <host> 151
Block it in the firewall
sudo ufw deny 151/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 151" -Direction Inbound -LocalPort 151 -Protocol TCP -Action Block # Windows
What is port 151 used for?
Port 151 is assigned by IANA to hems (HEMS).
Is port 151 TCP or UDP?
Port 151 is registered for TCP and UDP.
Is it safe to open port 151?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.
How do I check if port 151 is open?
On Linux run "ss -ltnup 'sport = :151'", on macOS "lsof -nP -i :151", and on Windows "netstat -ano | findstr :151" to see the local process. From another machine, "nmap -p 151 <host>" shows whether it is reachable.