HTTPfy

Port 529 (irc-serv)

IANA assigns port 529 to irc-serv: IRC-SERV.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
irc-serv TCP IRC-SERV Brian Tackett -
irc-serv UDP IRC-SERV Brian Tackett -

Check what is listening on port 529

Linux: is anything listening on TCP 529?
sudo ss -tlnp 'sport = :529'
Linux: UDP 529
sudo ss -ulnp 'sport = :529'
Linux / macOS: which process owns the port
sudo lsof -nP -i :529
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':529 '
Windows (Command Prompt)
netstat -ano | findstr :529
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 529 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 529
From Windows
Test-NetConnection HOST -Port 529
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 529

Block port 529 in the firewall

ufw
sudo ufw deny 529/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 529 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 529 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 529' -Direction Inbound -Protocol TCP -LocalPort 529 -Action Block
ufw
sudo ufw deny 529/udp
iptables
sudo iptables -A INPUT -p udp --dport 529 -j DROP
nftables
sudo nft add rule inet filter input udp dport 529 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 529' -Direction Inbound -Protocol UDP -LocalPort 529 -Action Block

Related ports

527stx528custix530courier531conference

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