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Port 19283 (keysrvr)

IANA assigns port 19283 to keysrvr: Key Server for SASSAFRAS.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
keysrvr TCP Key Server for SASSAFRAS Mark Valence -
keysrvr UDP Key Server for SASSAFRAS Mark Valence -

Check what is listening on port 19283

Linux: is anything listening on TCP 19283?
sudo ss -tlnp 'sport = :19283'
Linux: UDP 19283
sudo ss -ulnp 'sport = :19283'
Linux / macOS: which process owns the port
sudo lsof -nP -i :19283
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':19283 '
Windows (Command Prompt)
netstat -ano | findstr :19283
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 19283 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 19283
From Windows
Test-NetConnection HOST -Port 19283
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 19283

Block port 19283 in the firewall

ufw
sudo ufw deny 19283/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 19283 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 19283 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 19283' -Direction Inbound -Protocol TCP -LocalPort 19283 -Action Block
ufw
sudo ufw deny 19283/udp
iptables
sudo iptables -A INPUT -p udp --dport 19283 -j DROP
nftables
sudo nft add rule inet filter input udp dport 19283 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 19283' -Direction Inbound -Protocol UDP -LocalPort 19283 -Action Block

Related ports

19194ua-secureagent19220cora, cora-disc19315keyshadow19398mtrgtrans

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