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Port 650 (obex)

IANA assigns port 650 to obex: OBEX.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
obex TCP OBEX Jeff Garbers -
obex UDP OBEX Jeff Garbers -

Check what is listening on port 650

Linux: is anything listening on TCP 650?
sudo ss -tlnp 'sport = :650'
Linux: UDP 650
sudo ss -ulnp 'sport = :650'
Linux / macOS: which process owns the port
sudo lsof -nP -i :650
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':650 '
Windows (Command Prompt)
netstat -ano | findstr :650
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 650 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 650
From Windows
Test-NetConnection HOST -Port 650
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 650

Block port 650 in the firewall

ufw
sudo ufw deny 650/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 650 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 650 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 650' -Direction Inbound -Protocol TCP -LocalPort 650 -Action Block
ufw
sudo ufw deny 650/udp
iptables
sudo iptables -A INPUT -p udp --dport 650 -j DROP
nftables
sudo nft add rule inet filter input udp dport 650 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 650' -Direction Inbound -Protocol UDP -LocalPort 650 -Action Block

Related ports

648rrp649cadview-3d651ieee-mms652hello-port

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