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Port 1811 (scientia-sdb)

IANA assigns port 1811 to scientia-sdb: Scientia-SDB.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
scientia-sdb TCP Scientia-SDB SYSTEMS MANAGER -
scientia-sdb UDP Scientia-SDB SYSTEMS MANAGER -

Check what is listening on port 1811

Linux: is anything listening on TCP 1811?
sudo ss -tlnp 'sport = :1811'
Linux: UDP 1811
sudo ss -ulnp 'sport = :1811'
Linux / macOS: which process owns the port
sudo lsof -nP -i :1811
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':1811 '
Windows (Command Prompt)
netstat -ano | findstr :1811
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1811 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 1811
From Windows
Test-NetConnection HOST -Port 1811
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 1811

Block port 1811 in the firewall

ufw
sudo ufw deny 1811/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 1811 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 1811 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 1811' -Direction Inbound -Protocol TCP -LocalPort 1811 -Action Block
ufw
sudo ufw deny 1811/udp
iptables
sudo iptables -A INPUT -p udp --dport 1811 -j DROP
nftables
sudo nft add rule inet filter input udp dport 1811 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 1811' -Direction Inbound -Protocol UDP -LocalPort 1811 -Action Block

Related ports

1809oracle-vp11810jerand-lm1812RADIUS authentication1813RADIUS accounting

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