HTTPfy

Port 1841 (netopia-vo3)

IANA assigns port 1841 to netopia-vo3.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
netopia-vo3 TCP netopia-vo3 - -
netopia-vo3 UDP netopia-vo3 - -

Check what is listening on port 1841

Linux: is anything listening on TCP 1841?
sudo ss -tlnp 'sport = :1841'
Linux: UDP 1841
sudo ss -ulnp 'sport = :1841'
Linux / macOS: which process owns the port
sudo lsof -nP -i :1841
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':1841 '
Windows (Command Prompt)
netstat -ano | findstr :1841
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1841 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 1841
From Windows
Test-NetConnection HOST -Port 1841
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 1841

Block port 1841 in the firewall

ufw
sudo ufw deny 1841/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 1841 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 1841 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 1841' -Direction Inbound -Protocol TCP -LocalPort 1841 -Action Block
ufw
sudo ufw deny 1841/udp
iptables
sudo iptables -A INPUT -p udp --dport 1841 -j DROP
nftables
sudo nft add rule inet filter input udp dport 1841 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 1841' -Direction Inbound -Protocol UDP -LocalPort 1841 -Action Block

Related ports

1839netopia-vo11840netopia-vo21842netopia-vo41843netopia-vo5

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