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Port 83 (mit-ml-dev)

IANA assigns port 83 to mit-ml-dev: MIT ML Device.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
mit-ml-dev TCP MIT ML Device David Reed -
mit-ml-dev UDP MIT ML Device David Reed -

Check what is listening on port 83

Linux: is anything listening on TCP 83?
sudo ss -tlnp 'sport = :83'
Linux: UDP 83
sudo ss -ulnp 'sport = :83'
Linux / macOS: which process owns the port
sudo lsof -nP -i :83
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':83 '
Windows (Command Prompt)
netstat -ano | findstr :83
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 83 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 83
From Windows
Test-NetConnection HOST -Port 83
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 83

Block port 83 in the firewall

ufw
sudo ufw deny 83/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 83 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 83 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 83' -Direction Inbound -Protocol TCP -LocalPort 83 -Action Block
ufw
sudo ufw deny 83/udp
iptables
sudo iptables -A INPUT -p udp --dport 83 -j DROP
nftables
sudo nft add rule inet filter input udp dport 83 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 83' -Direction Inbound -Protocol UDP -LocalPort 83 -Action Block

Related ports

85mit-ml-dev80HTTP82xfer84ctf

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.