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Port 1606 (slm-api)

IANA assigns port 1606 to slm-api: Salutation Manager (SLM-API).

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
slm-api TCP Salutation Manager (SLM-API) Tohru Mori -
slm-api UDP Salutation Manager (SLM-API) Tohru Mori -

Check what is listening on port 1606

Linux: is anything listening on TCP 1606?
sudo ss -tlnp 'sport = :1606'
Linux: UDP 1606
sudo ss -ulnp 'sport = :1606'
Linux / macOS: which process owns the port
sudo lsof -nP -i :1606
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':1606 '
Windows (Command Prompt)
netstat -ano | findstr :1606
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1606 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 1606
From Windows
Test-NetConnection HOST -Port 1606
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 1606

Block port 1606 in the firewall

ufw
sudo ufw deny 1606/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 1606 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 1606 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 1606' -Direction Inbound -Protocol TCP -LocalPort 1606 -Action Block
ufw
sudo ufw deny 1606/udp
iptables
sudo iptables -A INPUT -p udp --dport 1606 -j DROP
nftables
sudo nft add rule inet filter input udp dport 1606 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 1606' -Direction Inbound -Protocol UDP -LocalPort 1606 -Action Block

Related ports

1604icabrowser1605slp1607stt1608smart-lm

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