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Port 3896 (sdo-tls)

IANA assigns port 3896 to sdo-tls: Simple Distributed Objects over TLS.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
sdo-tls TCP Simple Distributed Objects over TLS Alexander Philippou -
sdo-tls UDP Simple Distributed Objects over TLS Alexander Philippou -

Registry dates for this port: registered 2003-10.

Check what is listening on port 3896

Linux: is anything listening on TCP 3896?
sudo ss -tlnp 'sport = :3896'
Linux: UDP 3896
sudo ss -ulnp 'sport = :3896'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3896
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3896 '
Windows (Command Prompt)
netstat -ano | findstr :3896
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3896 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3896
From Windows
Test-NetConnection HOST -Port 3896
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3896

Block port 3896 in the firewall

ufw
sudo ufw deny 3896/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3896 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3896 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3896' -Direction Inbound -Protocol TCP -LocalPort 3896 -Action Block
ufw
sudo ufw deny 3896/udp
iptables
sudo iptables -A INPUT -p udp --dport 3896 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3896 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3896' -Direction Inbound -Protocol UDP -LocalPort 3896 -Action Block

Related ports

3894syam-agent3895syam-smc3897sdo-ssh3898senip

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