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Port 3091 (1ci-smcs)

IANA assigns port 3091 to 1ci-smcs: 1Ci Server Management.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
1ci-smcs TCP 1Ci Server Management Ralf Bensmann -
1ci-smcs UDP 1Ci Server Management Ralf Bensmann -

Check what is listening on port 3091

Linux: is anything listening on TCP 3091?
sudo ss -tlnp 'sport = :3091'
Linux: UDP 3091
sudo ss -ulnp 'sport = :3091'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3091
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3091 '
Windows (Command Prompt)
netstat -ano | findstr :3091
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3091 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3091
From Windows
Test-NetConnection HOST -Port 3091
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3091

Block port 3091 in the firewall

ufw
sudo ufw deny 3091/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3091 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3091 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3091' -Direction Inbound -Protocol TCP -LocalPort 3091 -Action Block
ufw
sudo ufw deny 3091/udp
iptables
sudo iptables -A INPUT -p udp --dport 3091 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3091 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3091' -Direction Inbound -Protocol UDP -LocalPort 3091 -Action Block

Related ports

3089ptk-alink3090stss3093rapidmq-center3094rapidmq-reg

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