Port 1992 (stun-p3, ipsendmsg)

IANA assigns port 1992 to stun-p3, ipsendmsg: cisco STUN Priority 3 port.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

stun-p3 TCP cisco STUN Priority 3 port - -

ipsendmsg TCP IPsendmsg
This entry records an unassigned but widespread use Bob Kummerfeld -

stun-p3 UDP cisco STUN Priority 3 port - -

ipsendmsg UDP IPsendmsg
This entry records an unassigned but widespread use Bob Kummerfeld -

Linux: is anything listening on TCP 1992?

sudo ss -tlnp 'sport = :1992'

Linux: UDP 1992

sudo ss -ulnp 'sport = :1992'

Linux / macOS: which process owns the port

sudo lsof -nP -i :1992

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':1992 '

Windows (Command Prompt)

netstat -ano | findstr :1992

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1992 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 1992

From Windows

Test-NetConnection HOST -Port 1992

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 1992

ufw

sudo ufw deny 1992/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 1992 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 1992 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 1992' -Direction Inbound -Protocol TCP -LocalPort 1992 -Action Block

ufw

sudo ufw deny 1992/udp

iptables

sudo iptables -A INPUT -p udp --dport 1992 -j DROP

nftables

sudo nft add rule inet filter input udp dport 1992 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block UDP 1992' -Direction Inbound -Protocol UDP -LocalPort 1992 -Action Block

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