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Port 4091 (ewinstaller)

IANA assigns port 4091 to ewinstaller: EminentWare Installer.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ewinstaller TCP EminentWare Installer - -
ewinstaller UDP EminentWare Installer - -

Check what is listening on port 4091

Linux: is anything listening on TCP 4091?
sudo ss -tlnp 'sport = :4091'
Linux: UDP 4091
sudo ss -ulnp 'sport = :4091'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4091
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4091 '
Windows (Command Prompt)
netstat -ano | findstr :4091
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4091 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4091
From Windows
Test-NetConnection HOST -Port 4091
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4091

Block port 4091 in the firewall

ufw
sudo ufw deny 4091/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4091 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4091 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4091' -Direction Inbound -Protocol TCP -LocalPort 4091 -Action Block
ufw
sudo ufw deny 4091/udp
iptables
sudo iptables -A INPUT -p udp --dport 4091 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4091 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4091' -Direction Inbound -Protocol UDP -LocalPort 4091 -Action Block

Related ports

4089opencore4090omasgport4092ewdgs4093pvxpluscs

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