- Answer only the networks that need the service (no open resolvers, relays or reflectors).
- UDP services can be abused for DDoS amplification: rate-limit or block them at the edge.
- Disable legacy test services that have no use in production.
Port 79: Finger
Port 79 is assigned by IANA to finger (Finger).
79
How finger works
Network servicesThe client sends a request to port 79 and the finger 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
- Network services
Is port 79 dangerous?
We have no specific security note for port 79. Its risk depends on the program actually listening on it. General advice for network services services:
IANA registry entries for port 79
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| finger | 79 | TCP, UDP | Finger Reported: Unauthorized use by some mail users (see [RFC4146] for details) | - | - |
// source: IANA service name and port number registry
Which program uses port 79, and is it reachable?
Linux
sudo ss -ltnup 'sport = :79' # process listening on 79
sudo lsof -nP -i :79macOS
sudo lsof -nP -i :79
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 79 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 79 netstat -ano | findstr :79
From another machine
nmap -p 79 -sV <host> sudo nmap -sU -p 79 <host> nc -zv <host> 79
Block it in the firewall
sudo ufw deny 79/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 79" -Direction Inbound -LocalPort 79 -Protocol TCP -Action Block # Windows
What is port 79 used for?
Port 79 is assigned by IANA to finger (Finger).
Is port 79 TCP or UDP?
Port 79 is registered for TCP and UDP.
Is it safe to open port 79?
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. Answer only the networks that need the service (no open resolvers, relays or reflectors).
How do I check if port 79 is open?
On Linux run "ss -ltnup 'sport = :79'", on macOS "lsof -nP -i :79", and on Windows "netstat -ano | findstr :79" to see the local process. From another machine, "nmap -p 79 <host>" shows whether it is reachable.
Other network services ports
:53 DNS tcp · udp · moderate risk :135 MS RPC tcp · udp · high risk :123 NTP udp · tcp · moderate risk :67 DHCP server udp · tcp · moderate risk :111 rpcbind tcp · udp · high risk :9100 Raw printing (JetDirect) tcp · udp · high risk :631 IPP / CUPS tcp · udp · high risk :5353 mDNS udp · tcp · moderate risk