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Port 3888 (ciphire-serv)

IANA assigns port 3888 to ciphire-serv: Ciphire Services.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ciphire-serv TCP Ciphire Services Lars Eilebrecht -
ciphire-serv UDP Ciphire Services Lars Eilebrecht -

Registry dates for this port: registered 2003-10.

Check what is listening on port 3888

Linux: is anything listening on TCP 3888?
sudo ss -tlnp 'sport = :3888'
Linux: UDP 3888
sudo ss -ulnp 'sport = :3888'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3888
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3888 '
Windows (Command Prompt)
netstat -ano | findstr :3888
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3888 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3888
From Windows
Test-NetConnection HOST -Port 3888
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3888

Block port 3888 in the firewall

ufw
sudo ufw deny 3888/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3888 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3888 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3888' -Direction Inbound -Protocol TCP -LocalPort 3888 -Action Block
ufw
sudo ufw deny 3888/udp
iptables
sudo iptables -A INPUT -p udp --dport 3888 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3888 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3888' -Direction Inbound -Protocol UDP -LocalPort 3888 -Action Block

Related ports

3886nei-management3887ciphire-data3889dandv-tester3890ndsconnect

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