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Port 1840 (netopia-vo2)

IANA assigns port 1840 to netopia-vo2.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
netopia-vo2 TCP netopia-vo2 - -
netopia-vo2 UDP netopia-vo2 - -

Check what is listening on port 1840

Linux: is anything listening on TCP 1840?
sudo ss -tlnp 'sport = :1840'
Linux: UDP 1840
sudo ss -ulnp 'sport = :1840'
Linux / macOS: which process owns the port
sudo lsof -nP -i :1840
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':1840 '
Windows (Command Prompt)
netstat -ano | findstr :1840
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1840 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 1840
From Windows
Test-NetConnection HOST -Port 1840
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 1840

Block port 1840 in the firewall

ufw
sudo ufw deny 1840/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 1840 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 1840 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 1840' -Direction Inbound -Protocol TCP -LocalPort 1840 -Action Block
ufw
sudo ufw deny 1840/udp
iptables
sudo iptables -A INPUT -p udp --dport 1840 -j DROP
nftables
sudo nft add rule inet filter input udp dport 1840 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 1840' -Direction Inbound -Protocol UDP -LocalPort 1840 -Action Block

Related ports

1838talnet1839netopia-vo11841netopia-vo31842netopia-vo4

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