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Port 5247 (capwap-data)

IANA assigns port 5247 to capwap-data: CAPWAP Data Protocol.

Registered (user) port, 1024-49151 UDP

Port 5247 is normally used over UDP; the checker tests TCP only, so a "filtered" result does not mean the UDP service is down.

IANA assignment

Service nameProtoDescriptionAssigneeReference
capwap-data UDP CAPWAP Data Protocol - RFC 5415

Check what is listening on port 5247

Linux: UDP 5247
sudo ss -ulnp 'sport = :5247'
Linux / macOS: which process owns the port
sudo lsof -nP -i :5247
Windows (Command Prompt)
netstat -ano | findstr :5247
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 5247

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 5247

Block port 5247 in the firewall

ufw
sudo ufw deny 5247/udp
iptables
sudo iptables -A INPUT -p udp --dport 5247 -j DROP
nftables
sudo nft add rule inet filter input udp dport 5247 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 5247' -Direction Inbound -Protocol UDP -LocalPort 5247 -Action Block

Related ports

5245downtools, downtools-disc5246capwap-control5248caacws5249caaclang2

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