HTTPfy

Port 4456 (prchat-server)

IANA assigns port 4456 to prchat-server: PR Chat Server.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
prchat-server TCP PR Chat Server - -
prchat-server UDP PR Chat Server - -

Check what is listening on port 4456

Linux: is anything listening on TCP 4456?
sudo ss -tlnp 'sport = :4456'
Linux: UDP 4456
sudo ss -ulnp 'sport = :4456'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4456
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4456 '
Windows (Command Prompt)
netstat -ano | findstr :4456
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4456 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4456
From Windows
Test-NetConnection HOST -Port 4456
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4456

Block port 4456 in the firewall

ufw
sudo ufw deny 4456/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4456 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4456 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4456' -Direction Inbound -Protocol TCP -LocalPort 4456 -Action Block
ufw
sudo ufw deny 4456/udp
iptables
sudo iptables -A INPUT -p udp --dport 4456 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4456 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4456' -Direction Inbound -Protocol UDP -LocalPort 4456 -Action Block

Related ports

4454nssagentmgr4455prchat-user4457prRegister4458mcp

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