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Port 21212 (trinket-agent)

IANA assigns port 21212 to trinket-agent: Distributed artificial intelligence.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference
trinket-agent TCP Distributed artificial intelligence Holvonix LLC -

Registry dates for this port: registered 2017-11-29.

Check what is listening on port 21212

Linux: is anything listening on TCP 21212?
sudo ss -tlnp 'sport = :21212'
Linux / macOS: which process owns the port
sudo lsof -nP -i :21212
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':21212 '
Windows (Command Prompt)
netstat -ano | findstr :21212
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 21212 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 21212
From Windows
Test-NetConnection HOST -Port 21212

Block port 21212 in the firewall

ufw
sudo ufw deny 21212/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 21212 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 21212 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 21212' -Direction Inbound -Protocol TCP -LocalPort 21212 -Action Block

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21000irtrans21010notezilla-lan21213cohesity-agent21221aigairserver

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