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Port 16991 (intel-rci-mp)

IANA assigns port 16991 to intel-rci-mp: INTEL-RCI-MP.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
intel-rci-mp TCP INTEL-RCI-MP Jane Dashevsky -
intel-rci-mp UDP INTEL-RCI-MP Jane Dashevsky -

Check what is listening on port 16991

Linux: is anything listening on TCP 16991?
sudo ss -tlnp 'sport = :16991'
Linux: UDP 16991
sudo ss -ulnp 'sport = :16991'
Linux / macOS: which process owns the port
sudo lsof -nP -i :16991
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':16991 '
Windows (Command Prompt)
netstat -ano | findstr :16991
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 16991 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 16991
From Windows
Test-NetConnection HOST -Port 16991
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 16991

Block port 16991 in the firewall

ufw
sudo ufw deny 16991/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 16991 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 16991 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 16991' -Direction Inbound -Protocol TCP -LocalPort 16991 -Action Block
ufw
sudo ufw deny 16991/udp
iptables
sudo iptables -A INPUT -p udp --dport 16991 -j DROP
nftables
sudo nft add rule inet filter input udp dport 16991 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 16991' -Direction Inbound -Protocol UDP -LocalPort 16991 -Action Block

Related ports

16900newbay-snc-mc16950sgcip16992amt-soap-http16993amt-soap-https

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