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Port 34964 (profinet-cm)

IANA assigns port 34964 to profinet-cm: PROFInet Context Manager.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
profinet-cm TCP PROFInet Context Manager PNO PROFIBUS Nutzerorganisation e.V. -
profinet-cm UDP PROFInet Context Manager PNO PROFIBUS Nutzerorganisation e.V. -

Registry dates for this port: registered 2004-11, last modified 2026-03-16.

Check what is listening on port 34964

Linux: is anything listening on TCP 34964?
sudo ss -tlnp 'sport = :34964'
Linux: UDP 34964
sudo ss -ulnp 'sport = :34964'
Linux / macOS: which process owns the port
sudo lsof -nP -i :34964
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':34964 '
Windows (Command Prompt)
netstat -ano | findstr :34964
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 34964 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 34964
From Windows
Test-NetConnection HOST -Port 34964
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 34964

Block port 34964 in the firewall

ufw
sudo ufw deny 34964/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 34964 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 34964 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 34964' -Direction Inbound -Protocol TCP -LocalPort 34964 -Action Block
ufw
sudo ufw deny 34964/udp
iptables
sudo iptables -A INPUT -p udp --dport 34964 -j DROP
nftables
sudo nft add rule inet filter input udp dport 34964 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 34964' -Direction Inbound -Protocol UDP -LocalPort 34964 -Action Block

Related ports

34962profinet-rt34963profinet-rtm34965profinet-cm-sec34966profinet-rt-sec

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