Hello,
Conduct the following tests;
1. Login to SWG web gui using the Management Port; else
2. Login to the terminal by connecting a Monitor on the VGA port
3. Refer http://www.symantec.com/docs/TECH96803
4. Sketch the network diagram and ensure the valid IP address is assigned
5. Management Port and LAN/WAN Port IP address should be from two separate IP Address Class.
6. Ensure no physical damage or malfunctioning cable connectivity.