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Port 616 (sco-sysmgr)

IANA assigns port 616 to sco-sysmgr: SCO System Administration Server.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
sco-sysmgr TCP SCO System Administration Server - -
sco-sysmgr UDP SCO System Administration Server - -

Check what is listening on port 616

Linux: is anything listening on TCP 616?
sudo ss -tlnp 'sport = :616'
Linux: UDP 616
sudo ss -ulnp 'sport = :616'
Linux / macOS: which process owns the port
sudo lsof -nP -i :616
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':616 '
Windows (Command Prompt)
netstat -ano | findstr :616
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 616 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 616
From Windows
Test-NetConnection HOST -Port 616
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 616

Block port 616 in the firewall

ufw
sudo ufw deny 616/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 616 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 616 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 616' -Direction Inbound -Protocol TCP -LocalPort 616 -Action Block
ufw
sudo ufw deny 616/udp
iptables
sudo iptables -A INPUT -p udp --dport 616 -j DROP
nftables
sudo nft add rule inet filter input udp dport 616 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 616' -Direction Inbound -Protocol UDP -LocalPort 616 -Action Block

Related ports

614sshell615sco-inetmgr617sco-dtmgr618dei-icda

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