Port 68: DHCP client
UDP 68 is the port for DHCP / BOOTP (client side). Local network only.
| Service | DHCP / BOOTP (client side) |
|---|---|
| Protocol | UDP |
| Exposure risk | Low: normally safe to expose |
| Range | Well-known (0–1023): binding needs root/admin on Unix |
Port 68 is UDP-only. UDP has no handshake, so no online checker can reliably tell open from filtered; test with the service's own client.
What port 68 does
The port DHCP clients listen on for offers and acknowledgements from the DHCP server on port 67.
Should port 68 be open?
Local network only.
Find what's listening on port 68
- Linux:
sudo ss -tulpn | grep :68 - macOS:
sudo lsof -nP -i :68 - Windows:
netstat -ano | findstr :68, then look up the PID in Task Manager.
Open or block it in a firewall
- ufw:
sudo ufw allow 68/udp(ordeny) - firewalld:
sudo firewall-cmd --add-port=68/udp --permanent && sudo firewall-cmd --reload - Windows:
New-NetFirewallRule -DisplayName "Port 68" -Direction Inbound -Protocol UDP -LocalPort 68 -Action Allow
Port assignment per the IANA Service Name and Transport Protocol Port Number Registry. Test several ports at once with the port scanner, or any port with the open port checker.
Questions about port 68
What is port 68 used for?
DHCP / BOOTP (client side). The port DHCP clients listen on for offers and acknowledgements from the DHCP server on port 67.
Is port 68 TCP or UDP?
UDP. DHCP client uses UDP port 68.
Is it safe to open port 68?
Low: normally safe to expose. Local network only.
How do I check if port 68 is open?
Port 68 is UDP-only, which has no handshake, so an online TCP checker can't confirm it. Use the service's own client to test, and check what is listening locally with
ss -ulpn | grep :68 (Linux) or netstat -ano | findstr :68 (Windows).