I have a service configured for in API and the system has both intranet and internet URL configured. However only intranet URL is working and internet URL is throwing bad gateway error.
Note: confirmed there is no firewall issue as it is opened for communications.
Can you provide more details on the error you are receiving? If you can provide the full error from the SSG log it would be appreciated.
When using the Route via HTTP(s) assertion this error can sometimes appear due to a read timeout. The value can be adjusted in the assertion properties
Route via HTTP(S) Assertion - CA API Gateway - 9.1 - CA Technologies Documentation
Is there a LB between internet client and gateway? Did the request really reach gateway? (need to check ssg log or audit event to confirm if the gateway receive the request, or tcpdump)
Sounds like network problem since intranet is working fine.