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Port 8403 (admind)

IANA assigns port 8403 to admind.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
admind TCP admind Aaron Bilbrey -
admind UDP admind Aaron Bilbrey -

Check what is listening on port 8403

Linux: is anything listening on TCP 8403?
sudo ss -tlnp 'sport = :8403'
Linux: UDP 8403
sudo ss -ulnp 'sport = :8403'
Linux / macOS: which process owns the port
sudo lsof -nP -i :8403
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':8403 '
Windows (Command Prompt)
netstat -ano | findstr :8403
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 8403 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 8403
From Windows
Test-NetConnection HOST -Port 8403
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 8403

Block port 8403 in the firewall

ufw
sudo ufw deny 8403/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 8403 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 8403 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 8403' -Direction Inbound -Protocol TCP -LocalPort 8403 -Action Block
ufw
sudo ufw deny 8403/udp
iptables
sudo iptables -A INPUT -p udp --dport 8403 -j DROP
nftables
sudo nft add rule inet filter input udp dport 8403 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 8403' -Direction Inbound -Protocol UDP -LocalPort 8403 -Action Block

Related ports

3279admind8401sabarsd8402abarsd8404svcloud8405svbackup

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