HTTPfy

Port 493 (ticf-2)

IANA assigns port 493 to ticf-2: Transport Independent Convergence for FNA.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
ticf-2 TCP Transport Independent Convergence for FNA Mamoru Ito -
ticf-2 UDP Transport Independent Convergence for FNA Mamoru Ito -

Check what is listening on port 493

Linux: is anything listening on TCP 493?
sudo ss -tlnp 'sport = :493'
Linux: UDP 493
sudo ss -ulnp 'sport = :493'
Linux / macOS: which process owns the port
sudo lsof -nP -i :493
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':493 '
Windows (Command Prompt)
netstat -ano | findstr :493
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 493 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 493
From Windows
Test-NetConnection HOST -Port 493
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 493

Block port 493 in the firewall

ufw
sudo ufw deny 493/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 493 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 493 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 493' -Direction Inbound -Protocol TCP -LocalPort 493 -Action Block
ufw
sudo ufw deny 493/udp
iptables
sudo iptables -A INPUT -p udp --dport 493 -j DROP
nftables
sudo nft add rule inet filter input udp dport 493 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 493' -Direction Inbound -Protocol UDP -LocalPort 493 -Action Block

Related ports

491go-login492ticf-1494pov-ray495intecourier

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