HTTPfy

Port 405 (ncld)

IANA assigns port 405 to ncld.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
ncld TCP ncld Richard Jones -
ncld UDP ncld Richard Jones -

Check what is listening on port 405

Linux: is anything listening on TCP 405?
sudo ss -tlnp 'sport = :405'
Linux: UDP 405
sudo ss -ulnp 'sport = :405'
Linux / macOS: which process owns the port
sudo lsof -nP -i :405
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':405 '
Windows (Command Prompt)
netstat -ano | findstr :405
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 405 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 405
From Windows
Test-NetConnection HOST -Port 405
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 405

Block port 405 in the firewall

ufw
sudo ufw deny 405/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 405 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 405 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 405' -Direction Inbound -Protocol TCP -LocalPort 405 -Action Block
ufw
sudo ufw deny 405/udp
iptables
sudo iptables -A INPUT -p udp --dport 405 -j DROP
nftables
sudo nft add rule inet filter input udp dport 405 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 405' -Direction Inbound -Protocol UDP -LocalPort 405 -Action Block

Related ports

403decap404nced406imsp407timbuktu

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