I think the routing has an issue on this. Be sure to verify if it has no problem in network

Check to see if traffic is reaching the IAM device: Check to see if traffic from external IP addresses is reaching the IAM device. You may sample the traffic and see if it is being sent to the IAM device using tools like tcpdump or Wireshark.

Examine Traffic Classification Rules: The Sangfor IAM 5200 device identifies and categorizes network traffic using traffic classification rules. Ascertain that proper traffic categorization rules are in place to appropriately identify traffic destined for your bespoke application. Check that the IP addresses you supplied in the rule fit the traffic categorization criteria and are properly set.

To further investigate the issue with the Sangfor IAM 5200 device not catching traffic destined to the custom application, you can perform the following steps:

Verify the configuration: Double-check the configuration settings you made for the custom application and the bandwidth management rule. Ensure that you have correctly added the external server IP addresses and assigned the appropriate high bandwidth limit.

Check network connectivity: Ensure that there is proper network connectivity between the Sangfor IAM 5200 device and the external servers. Verify that the device can reach the IP addresses of the external servers by performing network connectivity tests such as ping or traceroute.

Review firewall and routing rules: Check if there are any firewall or routing rules that could be blocking or redirecting the traffic before it reaches the Sangfor IAM 5200 device. Make sure that the necessary rules are in place to allow traffic from the external IP addresses to reach the device.

Analyze traffic logs: Check the device's traffic logs or monitoring tools to see if any traffic matching the custom application's IP addresses is being logged. Look for any indications of dropped or blocked traffic, as well as any unexpected routing or NAT behavior.

Debugging and troubleshooting tools: Utilize the debugging and troubleshooting tools provided by the Sangfor IAM 5200 device to gain more insights into the traffic flow and rule matching process. These tools may include packet captures, traffic analysis, or diagnostic commands specific to the device.

Consult vendor documentation or support: If you are unable to identify the issue or resolve it on your own, refer to the vendor's documentation, user guides, or support resources. Contacting the vendor's technical support team can also provide assistance in troubleshooting and resolving the issue.

By following these steps and thoroughly investigating the configuration, network connectivity, traffic logs, and utilizing debugging tools, you should be able to identify the cause of the issue and take appropriate actions to resolve it.

Ensure that there is proper network connectivity between the Sangfor IAM 5200 device and the external servers. Verify that the device can reach the IP addresses of the external servers by performing network connectivity tests such as ping or traceroute.

network connectivity, traffic logs, and utilizing debugging tools, you should be able to identify the cause of the issue and take appropriate actions to resolve it.