HTTPfy

Port 3242 (sdp-id-port)

IANA assigns port 3242 to sdp-id-port: Session Description ID.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
sdp-id-port TCP Session Description ID Greg Rose 2 -
sdp-id-port UDP Session Description ID Greg Rose 2 -

Registry dates for this port: registered 2002-02.

Check what is listening on port 3242

Linux: is anything listening on TCP 3242?
sudo ss -tlnp 'sport = :3242'
Linux: UDP 3242
sudo ss -ulnp 'sport = :3242'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3242
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3242 '
Windows (Command Prompt)
netstat -ano | findstr :3242
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3242 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3242
From Windows
Test-NetConnection HOST -Port 3242
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3242

Block port 3242 in the firewall

ufw
sudo ufw deny 3242/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3242 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3242 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3242' -Direction Inbound -Protocol TCP -LocalPort 3242 -Action Block
ufw
sudo ufw deny 3242/udp
iptables
sudo iptables -A INPUT -p udp --dport 3242 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3242 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3242' -Direction Inbound -Protocol UDP -LocalPort 3242 -Action Block

Related ports

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