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Port 3535 (ms-la)

IANA assigns port 3535 to ms-la: MS-LA.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ms-la TCP MS-LA Eric Ledoux -
ms-la UDP MS-LA Eric Ledoux -

Check what is listening on port 3535

Linux: is anything listening on TCP 3535?
sudo ss -tlnp 'sport = :3535'
Linux: UDP 3535
sudo ss -ulnp 'sport = :3535'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3535
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3535 '
Windows (Command Prompt)
netstat -ano | findstr :3535
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3535 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3535
From Windows
Test-NetConnection HOST -Port 3535
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3535

Block port 3535 in the firewall

ufw
sudo ufw deny 3535/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3535 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3535 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3535' -Direction Inbound -Protocol TCP -LocalPort 3535 -Action Block
ufw
sudo ufw deny 3535/udp
iptables
sudo iptables -A INPUT -p udp --dport 3535 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3535 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3535' -Direction Inbound -Protocol UDP -LocalPort 3535 -Action Block

Related ports

3533raven-rdp3534urld-port3536snac3537ni-visa-remote

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