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Port 4845 (wcr-remlib)

IANA assigns port 4845 to wcr-remlib: WordCruncher Remote Library Service.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
wcr-remlib TCP WordCruncher Remote Library Service Jason Dzubak -
wcr-remlib UDP WordCruncher Remote Library Service Jason Dzubak -

Registry dates for this port: registered 2008-03-17.

Check what is listening on port 4845

Linux: is anything listening on TCP 4845?
sudo ss -tlnp 'sport = :4845'
Linux: UDP 4845
sudo ss -ulnp 'sport = :4845'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4845
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4845 '
Windows (Command Prompt)
netstat -ano | findstr :4845
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4845 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4845
From Windows
Test-NetConnection HOST -Port 4845
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4845

Block port 4845 in the firewall

ufw
sudo ufw deny 4845/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4845 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4845 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4845' -Direction Inbound -Protocol TCP -LocalPort 4845 -Action Block
ufw
sudo ufw deny 4845/udp
iptables
sudo iptables -A INPUT -p udp --dport 4845 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4845 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4845' -Direction Inbound -Protocol UDP -LocalPort 4845 -Action Block

Related ports

4843opcua-tls4844gw-log4846contamac-icm, contamac_icm4847wfc

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