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Port 3822 (acp-discovery)

IANA assigns port 3822 to acp-discovery: Compute Pool Discovery.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
acp-discovery TCP Compute Pool Discovery - -
acp-discovery UDP Compute Pool Discovery - -

Check what is listening on port 3822

Linux: is anything listening on TCP 3822?
sudo ss -tlnp 'sport = :3822'
Linux: UDP 3822
sudo ss -ulnp 'sport = :3822'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3822
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3822 '
Windows (Command Prompt)
netstat -ano | findstr :3822
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3822 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3822
From Windows
Test-NetConnection HOST -Port 3822
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3822

Block port 3822 in the firewall

ufw
sudo ufw deny 3822/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3822 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3822 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3822' -Direction Inbound -Protocol TCP -LocalPort 3822 -Action Block
ufw
sudo ufw deny 3822/udp
iptables
sudo iptables -A INPUT -p udp --dport 3822 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3822 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3822' -Direction Inbound -Protocol UDP -LocalPort 3822 -Action Block

Related ports

3820scp3821pmcp3823acp-conduit3824acp-policy

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