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Port 5352 (dns-llq)

IANA assigns port 5352 to dns-llq: DNS Long-Lived Queries.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
dns-llq TCP DNS Long-Lived Queries Stuart Cheshire RFC 8764
dns-llq UDP DNS Long-Lived Queries Stuart Cheshire RFC 8764

Registry dates for this port: registered 2005-08, last modified 2019-08-26.

Check what is listening on port 5352

Linux: is anything listening on TCP 5352?
sudo ss -tlnp 'sport = :5352'
Linux: UDP 5352
sudo ss -ulnp 'sport = :5352'
Linux / macOS: which process owns the port
sudo lsof -nP -i :5352
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':5352 '
Windows (Command Prompt)
netstat -ano | findstr :5352
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 5352 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 5352
From Windows
Test-NetConnection HOST -Port 5352
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 5352

Block port 5352 in the firewall

ufw
sudo ufw deny 5352/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 5352 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 5352 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 5352' -Direction Inbound -Protocol TCP -LocalPort 5352 -Action Block
ufw
sudo ufw deny 5352/udp
iptables
sudo iptables -A INPUT -p udp --dport 5352 -j DROP
nftables
sudo nft add rule inet filter input udp dport 5352 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 5352' -Direction Inbound -Protocol UDP -LocalPort 5352 -Action Block

Related ports

5350pcp-multicast5351pcp5353mDNS (Bonjour)5354mdnsresponder

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.