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Port 5356 (ms-smlbiz)

IANA assigns port 5356 to ms-smlbiz: Microsoft Small Business.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ms-smlbiz TCP Microsoft Small Business Gopikrishna Sandra -
ms-smlbiz UDP Microsoft Small Business Gopikrishna Sandra -

Registry dates for this port: registered 2005-02.

Check what is listening on port 5356

Linux: is anything listening on TCP 5356?
sudo ss -tlnp 'sport = :5356'
Linux: UDP 5356
sudo ss -ulnp 'sport = :5356'
Linux / macOS: which process owns the port
sudo lsof -nP -i :5356
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':5356 '
Windows (Command Prompt)
netstat -ano | findstr :5356
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 5356 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 5356
From Windows
Test-NetConnection HOST -Port 5356
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 5356

Block port 5356 in the firewall

ufw
sudo ufw deny 5356/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 5356 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 5356 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 5356' -Direction Inbound -Protocol TCP -LocalPort 5356 -Action Block
ufw
sudo ufw deny 5356/udp
iptables
sudo iptables -A INPUT -p udp --dport 5356 -j DROP
nftables
sudo nft add rule inet filter input udp dport 5356 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 5356' -Direction Inbound -Protocol UDP -LocalPort 5356 -Action Block

Related ports

5354mdnsresponder5355LLMNR5357wsdapi5358wsdapi-s

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