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Port 7121 (virprot-lm)

IANA assigns port 7121 to virprot-lm: Virtual Prototypes License Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
virprot-lm TCP Virtual Prototypes License Manager Victor Galis -
virprot-lm UDP Virtual Prototypes License Manager Victor Galis -

Check what is listening on port 7121

Linux: is anything listening on TCP 7121?
sudo ss -tlnp 'sport = :7121'
Linux: UDP 7121
sudo ss -ulnp 'sport = :7121'
Linux / macOS: which process owns the port
sudo lsof -nP -i :7121
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':7121 '
Windows (Command Prompt)
netstat -ano | findstr :7121
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 7121 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 7121
From Windows
Test-NetConnection HOST -Port 7121
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 7121

Block port 7121 in the firewall

ufw
sudo ufw deny 7121/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 7121 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 7121 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 7121' -Direction Inbound -Protocol TCP -LocalPort 7121 -Action Block
ufw
sudo ufw deny 7121/udp
iptables
sudo iptables -A INPUT -p udp --dport 7121 -j DROP
nftables
sudo nft add rule inet filter input udp dport 7121 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 7121' -Direction Inbound -Protocol UDP -LocalPort 7121 -Action Block

Related ports

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