HTTPfy

Port 397 (mptn)

IANA assigns port 397 to mptn: Multi Protocol Trans. Net..

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
mptn TCP Multi Protocol Trans. Net. Soumitra Sarkar -
mptn UDP Multi Protocol Trans. Net. Soumitra Sarkar -

Check what is listening on port 397

Linux: is anything listening on TCP 397?
sudo ss -tlnp 'sport = :397'
Linux: UDP 397
sudo ss -ulnp 'sport = :397'
Linux / macOS: which process owns the port
sudo lsof -nP -i :397
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':397 '
Windows (Command Prompt)
netstat -ano | findstr :397
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 397 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 397
From Windows
Test-NetConnection HOST -Port 397
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 397

Block port 397 in the firewall

ufw
sudo ufw deny 397/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 397 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 397 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 397' -Direction Inbound -Protocol TCP -LocalPort 397 -Action Block
ufw
sudo ufw deny 397/udp
iptables
sudo iptables -A INPUT -p udp --dport 397 -j DROP
nftables
sudo nft add rule inet filter input udp dport 397 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 397' -Direction Inbound -Protocol UDP -LocalPort 397 -Action Block

Related ports

395netcp396netware-ip398kryptolan399iso-tsap-c2

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