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Port 3398 (mercantile)

IANA assigns port 3398 to mercantile: Mercantile.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
mercantile TCP Mercantile Erik Kragh Jensen -
mercantile UDP Mercantile Erik Kragh Jensen -

Check what is listening on port 3398

Linux: is anything listening on TCP 3398?
sudo ss -tlnp 'sport = :3398'
Linux: UDP 3398
sudo ss -ulnp 'sport = :3398'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3398
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3398 '
Windows (Command Prompt)
netstat -ano | findstr :3398
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3398 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3398
From Windows
Test-NetConnection HOST -Port 3398
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3398

Block port 3398 in the firewall

ufw
sudo ufw deny 3398/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3398 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3398 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3398' -Direction Inbound -Protocol TCP -LocalPort 3398 -Action Block
ufw
sudo ufw deny 3398/udp
iptables
sudo iptables -A INPUT -p udp --dport 3398 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3398 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3398' -Direction Inbound -Protocol UDP -LocalPort 3398 -Action Block

Related ports

3396printer-agent, printer_agent3397cloanto-lm3399csms3400csms2

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