Legacy protocols ports
13 legacy protocols ports: what each one does, its protocol, and whether it is secure by default.
SubnetKit lists 13 legacy protocols ports, using TCP/UDP, TCP, UDP. 13 of 13 are formally registered with IANA rather than just a widely followed convention.
None of the legacy protocols ports here are encrypted by default. Treat traffic on any of them as plain text unless you add TLS, SSH, or a VPN tunnel yourself.
Click any port below for its full page: what it does, its protocol, and whether it is safe to expose.
| Port | Service | Protocol | What it does |
|---|---|---|---|
| 7 | Echo | TCP/UDP | Echo Protocol |
| 9 | Discard | TCP/UDP | Discard Protocol |
| 13 | Daytime | TCP/UDP | Daytime Protocol |
| 17 | QOTD | TCP/UDP | Quote of the Day |
| 19 | Chargen | TCP/UDP | Character Generator Protocol |
| 37 | Time Protocol | TCP/UDP | Time Protocol |
| 43 | WHOIS | TCP | WHOIS protocol |
| 70 | Gopher | TCP | Gopher protocol |
| 79 | Finger | TCP | Finger protocol |
| 113 | Ident | TCP | Identification Protocol |
| 119 | NNTP | TCP | Network News Transfer Protocol |
| 517 | Talk | UDP | Talk protocol |
| 518 | ntalk | UDP | ntalk (Talk protocol, new version) |
Frequently asked questions
Which ports are in the Legacy protocols category?
port 7 (Echo), port 9 (Discard), port 13 (Daytime), port 17 (QOTD), port 19 (Chargen), port 37 (Time Protocol), port 43 (WHOIS), port 70 (Gopher), port 79 (Finger), port 113 (Ident), port 119 (NNTP), port 517 (Talk) and port 518 (ntalk).
How many legacy protocols ports does SubnetKit list?
13, covering TCP/UDP, TCP, UDP. 13 of them are formally registered with IANA.
Are legacy protocols ports secure by default?
No. None of the legacy protocols ports here are encrypted by default; wrap them in TLS, SSH, or a VPN if you need to protect the traffic.
Which legacy protocols port has the lowest number?
Port 7 (Echo). Port 7 is the Echo Protocol, which simply sends back whatever data it receives. It was designed for testing round-trip network connectivity and is rarely enabled today because it can be abused for denial-of-service amplification.