- Do not expose remote administration directly: use a VPN or a zero-trust access proxy.
- Require MFA or key-based authentication and lock out brute-force attempts.
- Log every login and alert on new source addresses.
Port 5161: SNMP over SSH Transport Model
Port 5161 is assigned by IANA to snmpssh (SNMP over SSH Transport Model).
How snmpssh works
Remote accessThe client opens a session to port 5161: each command typed is sent to the server, which runs it and returns the output.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Remote access
Is port 5161 dangerous?
We have no specific security note for port 5161. Its risk depends on the program actually listening on it. General advice for remote access services:
IANA registry entries for port 5161
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| snmpssh | 5161 | TCP | SNMP over SSH Transport Model | RFC 5592 | - |
| - | 5161 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 5161, and is it reachable?
Linux
sudo ss -ltnup 'sport = :5161' # process listening on 5161
sudo lsof -nP -i :5161macOS
sudo lsof -nP -i :5161
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 5161 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 5161 netstat -ano | findstr :5161
From another machine
nmap -p 5161 -sV <host> nc -zv <host> 5161
Block it in the firewall
sudo ufw deny 5161/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 5161" -Direction Inbound -LocalPort 5161 -Protocol TCP -Action Block # Windows
What is port 5161 used for?
Port 5161 is assigned by IANA to snmpssh (SNMP over SSH Transport Model).
Is port 5161 TCP or UDP?
Port 5161 is registered for TCP.
Is it safe to open port 5161?
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. Do not expose remote administration directly: use a VPN or a zero-trust access proxy.
How do I check if port 5161 is open?
On Linux run "ss -ltnup 'sport = :5161'", on macOS "lsof -nP -i :5161", and on Windows "netstat -ano | findstr :5161" to see the local process. From another machine, "nmap -p 5161 <host>" shows whether it is reachable.