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ProtocolPorts

Port reference

Port 119 (TCP) – NNTP (Usenet News)

Network News Transfer Protocol that distributes and serves Usenet newsgroup articles.

tcpWell-known

Quick facts

Transport
tcp
Category
Well-known
TLS
Cleartext
Risk level
High

Frequently targeted — restrict exposure and harden it.

Default state

Open on Usenet news servers; cleartext by default unless TLS (NNTPS, port 563) is used.

What is port 119 used for?

Port 119 is the default for NNTP, the Network News Transfer Protocol behind Usenet. News servers use it to swap articles with other servers and to let people read and post to newsgroups; clients like Thunderbird and dedicated newsreaders connect over it, and server software such as INN or Diablo listens on it. The encrypted variant, NNTPS, runs on port 563.

When would you open it?

Open port 119 only if you run a Usenet news server and want clients or peer servers to connect to it. Since plain 119 is unencrypted, most operators today prefer to offer access over NNTPS on 563 instead and keep 119 for legacy peers.

Is it safe to open?

Plain NNTP sends logins in cleartext and a misconfigured server can become an open relay for spam, so require authentication and prefer TLS (NNTPS on 563). See the security notes below.

How to check if this port is open

Linux
ss -tulpn | grep :119
nmap -p 119 <target>
Windows
netstat -ano | findstr :119
Test-NetConnection <host> -Port 119
macOS
lsof -i :119
nmap -p 119 <target>

How to open this port on your router

To reach this service from outside your network, forward the port on your router:

  1. Open your router's admin page (usually http://192.168.1.1 or http://192.168.0.1) and sign in.
  2. Find the "Port Forwarding" section — it may be called NAT, Virtual Server, or Applications & Gaming.
  3. Add a rule forwarding external port 119 to your device's local IP, internal port 119, protocol TCP.
  4. Save and reboot the router if prompted, then test the port from outside your network.

Only forward ports you understand — it exposes that device to the public internet. For remote admin access, a VPN is safer than forwarding the port.

Allow this port through the firewall

Linux (ufw)
sudo ufw allow 119/tcp
Linux (firewalld)
sudo firewall-cmd --permanent --add-port=119/tcp
sudo firewall-cmd --reload
Linux (iptables)
sudo iptables -A INPUT -p tcp --dport 119 -j ACCEPT
Windows
New-NetFirewallRule -DisplayName "Allow 119" -Direction Inbound -Protocol TCP -LocalPort 119 -Action Allow

Security & risks

Use a secure alternative

This is a legacy or cleartext protocol. Prefer the encrypted equivalent:

Port 563

Common attacks

  • Cleartext credential capture during AUTHINFO login
  • Open relay / unauthorized posting and spam injection
  • Brute-force authentication against subscriber accounts
  • Abuse for distributing pirated or illegal binaries

Hardening

  • Require TLS via NNTPS (port 563) and disable plaintext AUTHINFO
  • Enforce authentication and disable anonymous posting/reading
  • Restrict peering and posting to known, authorized hosts
  • Patch the news server (INN, Diablo) and rate-limit connections

How to block this port

Linux (ufw)
sudo ufw deny 119/tcp
Linux (firewalld)
sudo firewall-cmd --permanent --remove-port=119/tcp
sudo firewall-cmd --reload
Linux (iptables)
sudo iptables -A INPUT -p tcp --dport 119 -j DROP
Windows
New-NetFirewallRule -DisplayName "Block 119" -Direction Inbound -Protocol TCP -LocalPort 119 -Action Block

nmap snippet

nmap -p119 --script nntp-ntlm-info,banner <target>

Replace <target> with the host or range you're authorized to scan.

Related ports

Port 563Port 25Port 110Port 143

Frequently asked questions

Is NNTP on port 119 encrypted?
No. Plain NNTP on port 119 is cleartext, including AUTHINFO credentials. Use NNTPS on port 563, which wraps NNTP in TLS, to protect logins and traffic.
Why is an NNTP server a security concern?
Open or weakly authenticated news servers get abused as spam relays and for distributing illegal binaries, and cleartext logins expose subscriber credentials to sniffing.

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