HTTPfy

Port 2891 (cinegrfx-elmd)

IANA assigns port 2891 to cinegrfx-elmd: CINEGRFX-ELMD License Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
cinegrfx-elmd TCP CINEGRFX-ELMD License Manager Greg Ercolano 2 -
cinegrfx-elmd UDP CINEGRFX-ELMD License Manager Greg Ercolano 2 -

Check what is listening on port 2891

Linux: is anything listening on TCP 2891?
sudo ss -tlnp 'sport = :2891'
Linux: UDP 2891
sudo ss -ulnp 'sport = :2891'
Linux / macOS: which process owns the port
sudo lsof -nP -i :2891
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':2891 '
Windows (Command Prompt)
netstat -ano | findstr :2891
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 2891 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 2891
From Windows
Test-NetConnection HOST -Port 2891
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 2891

Block port 2891 in the firewall

ufw
sudo ufw deny 2891/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 2891 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 2891 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 2891' -Direction Inbound -Protocol TCP -LocalPort 2891 -Action Block
ufw
sudo ufw deny 2891/udp
iptables
sudo iptables -A INPUT -p udp --dport 2891 -j DROP
nftables
sudo nft add rule inet filter input udp dport 2891 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 2891' -Direction Inbound -Protocol UDP -LocalPort 2891 -Action Block

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2889rsom2890cspclmulti2892snifferdata2893vseconnector

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