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Port 613 (hmmp-op)

IANA assigns port 613 to hmmp-op: HMMP Operation.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
hmmp-op TCP HMMP Operation Andrew Sinclair -
hmmp-op UDP HMMP Operation Andrew Sinclair -

Check what is listening on port 613

Linux: is anything listening on TCP 613?
sudo ss -tlnp 'sport = :613'
Linux: UDP 613
sudo ss -ulnp 'sport = :613'
Linux / macOS: which process owns the port
sudo lsof -nP -i :613
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':613 '
Windows (Command Prompt)
netstat -ano | findstr :613
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 613 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 613
From Windows
Test-NetConnection HOST -Port 613
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 613

Block port 613 in the firewall

ufw
sudo ufw deny 613/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 613 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 613 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 613' -Direction Inbound -Protocol TCP -LocalPort 613 -Action Block
ufw
sudo ufw deny 613/udp
iptables
sudo iptables -A INPUT -p udp --dport 613 -j DROP
nftables
sudo nft add rule inet filter input udp dport 613 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 613' -Direction Inbound -Protocol UDP -LocalPort 613 -Action Block

Related ports

611npmp-gui612hmmp-ind614sshell615sco-inetmgr

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