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Port 41 (graphics)

IANA assigns port 41 to graphics: Graphics.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
graphics TCP Graphics - -
graphics UDP Graphics - -

Check what is listening on port 41

Linux: is anything listening on TCP 41?
sudo ss -tlnp 'sport = :41'
Linux: UDP 41
sudo ss -ulnp 'sport = :41'
Linux / macOS: which process owns the port
sudo lsof -nP -i :41
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':41 '
Windows (Command Prompt)
netstat -ano | findstr :41
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 41 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 41
From Windows
Test-NetConnection HOST -Port 41
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 41

Block port 41 in the firewall

ufw
sudo ufw deny 41/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 41 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 41 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 41' -Direction Inbound -Protocol TCP -LocalPort 41 -Action Block
ufw
sudo ufw deny 41/udp
iptables
sudo iptables -A INPUT -p udp --dport 41 -j DROP
nftables
sudo nft add rule inet filter input udp dport 41 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 41' -Direction Inbound -Protocol UDP -LocalPort 41 -Action Block

Related ports

38rap39rlp42name, nameserver43nicname

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