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Port 4013 (acl-manager)

IANA assigns port 4013 to acl-manager: ACL Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
acl-manager TCP ACL Manager Toru Murai -
acl-manager UDP ACL Manager Toru Murai -

Check what is listening on port 4013

Linux: is anything listening on TCP 4013?
sudo ss -tlnp 'sport = :4013'
Linux: UDP 4013
sudo ss -ulnp 'sport = :4013'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4013
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4013 '
Windows (Command Prompt)
netstat -ano | findstr :4013
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4013 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4013
From Windows
Test-NetConnection HOST -Port 4013
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4013

Block port 4013 in the firewall

ufw
sudo ufw deny 4013/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4013 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4013 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4013' -Direction Inbound -Protocol TCP -LocalPort 4013 -Action Block
ufw
sudo ufw deny 4013/udp
iptables
sudo iptables -A INPUT -p udp --dport 4013 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4013 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4013' -Direction Inbound -Protocol UDP -LocalPort 4013 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.