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Port 549 (idfp)

IANA assigns port 549 to idfp: IDFP.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
idfp TCP IDFP Ramana Kovi -
idfp UDP IDFP Ramana Kovi -

Check what is listening on port 549

Linux: is anything listening on TCP 549?
sudo ss -tlnp 'sport = :549'
Linux: UDP 549
sudo ss -ulnp 'sport = :549'
Linux / macOS: which process owns the port
sudo lsof -nP -i :549
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':549 '
Windows (Command Prompt)
netstat -ano | findstr :549
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 549 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 549
From Windows
Test-NetConnection HOST -Port 549
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 549

Block port 549 in the firewall

ufw
sudo ufw deny 549/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 549 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 549 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 549' -Direction Inbound -Protocol TCP -LocalPort 549 -Action Block
ufw
sudo ufw deny 549/udp
iptables
sudo iptables -A INPUT -p udp --dport 549 -j DROP
nftables
sudo nft add rule inet filter input udp dport 549 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 549' -Direction Inbound -Protocol UDP -LocalPort 549 -Action Block

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547DHCPv6 server548AFP550new-rwho551cybercash

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