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Port 4592 (hrpd-ith-at-an)

IANA assigns port 4592 to hrpd-ith-at-an: HRPD-ITH (AT-AN).

Registered (user) port, 1024-49151 UDP

Port 4592 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
hrpd-ith-at-an UDP HRPD-ITH (AT-AN) David Ott -

Registry dates for this port: registered 2008-06-05.

Check what is listening on port 4592

Linux: UDP 4592
sudo ss -ulnp 'sport = :4592'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4592
Windows (Command Prompt)
netstat -ano | findstr :4592
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 4592

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4592

Block port 4592 in the firewall

ufw
sudo ufw deny 4592/udp
iptables
sudo iptables -A INPUT -p udp --dport 4592 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4592 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4592' -Direction Inbound -Protocol UDP -LocalPort 4592 -Action Block

Related ports

4590rid4591l3t-at-an4593ipt-anri-anri4594ias-session

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