Port 3868 (diameter)

IANA assigns port 3868 to diameter: DIAMETER.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference

diameter TCP DIAMETER - -

diameter SCTP DIAMETER - RFC 3588

Linux: is anything listening on TCP 3868?

sudo ss -tlnp 'sport = :3868'

Linux / macOS: which process owns the port

sudo lsof -nP -i :3868

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':3868 '

Windows (Command Prompt)

netstat -ano | findstr :3868

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3868 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 3868

From Windows

Test-NetConnection HOST -Port 3868

ufw

sudo ufw deny 3868/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 3868 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 3868 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 3868' -Direction Inbound -Protocol TCP -LocalPort 3868 -Action Block

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