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Port 16368 (netserialext4)

IANA assigns port 16368 to netserialext4: Network Serial Extension Ports Four.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
netserialext4 TCP Network Serial Extension Ports Four Michael J Hoy -
netserialext4 UDP Network Serial Extension Ports Four Michael J Hoy -

Check what is listening on port 16368

Linux: is anything listening on TCP 16368?
sudo ss -tlnp 'sport = :16368'
Linux: UDP 16368
sudo ss -ulnp 'sport = :16368'
Linux / macOS: which process owns the port
sudo lsof -nP -i :16368
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':16368 '
Windows (Command Prompt)
netstat -ano | findstr :16368
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 16368 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 16368
From Windows
Test-NetConnection HOST -Port 16368
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 16368

Block port 16368 in the firewall

ufw
sudo ufw deny 16368/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 16368 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 16368 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 16368' -Direction Inbound -Protocol TCP -LocalPort 16368 -Action Block
ufw
sudo ufw deny 16368/udp
iptables
sudo iptables -A INPUT -p udp --dport 16368 -j DROP
nftables
sudo nft add rule inet filter input udp dport 16368 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 16368' -Direction Inbound -Protocol UDP -LocalPort 16368 -Action Block

Related ports

16361netserialext216367netserialext316384connected16385rdgs

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