HTTPfy

Port 92 (npp)

IANA assigns port 92 to npp: Network Printing Protocol.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
npp TCP Network Printing Protocol Louis Mamakos -
npp UDP Network Printing Protocol Louis Mamakos -

Check what is listening on port 92

Linux: is anything listening on TCP 92?
sudo ss -tlnp 'sport = :92'
Linux: UDP 92
sudo ss -ulnp 'sport = :92'
Linux / macOS: which process owns the port
sudo lsof -nP -i :92
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':92 '
Windows (Command Prompt)
netstat -ano | findstr :92
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 92 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 92
From Windows
Test-NetConnection HOST -Port 92
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 92

Block port 92 in the firewall

ufw
sudo ufw deny 92/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 92 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 92 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 92' -Direction Inbound -Protocol TCP -LocalPort 92 -Action Block
ufw
sudo ufw deny 92/udp
iptables
sudo iptables -A INPUT -p udp --dport 92 -j DROP
nftables
sudo nft add rule inet filter input udp dport 92 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 92' -Direction Inbound -Protocol UDP -LocalPort 92 -Action Block

Related ports

4045npp90dnsix91mit-dov93dcp94objcall

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