@Ananya Sarkar Azure firewall health can be monitored using the Firewall health state metric.
Firewall health state - Indicates the health of the firewall based on SNAT port availability.
Unit: percent
This metric has two dimensions:
Status: Possible values are Healthy, Degraded, Unhealthy.
Reason: Indicates the reason for the corresponding status of the firewall.
If SNAT ports are used > 95%, they are considered exhausted and the health is 50% with status=Degraded and reason=SNAT port. The firewall keeps processing traffic and existing connections are not affected. However, new connections may not be established intermittently.
If SNAT ports are used < 95%, then firewall is considered healthy and health is shown as 100%.
If no SNAT ports usage is reported, health is shown as 0%.
Please also note that the Azure Firewall's initial throughput capacity is 2.5 - 3 Gbps and it scales out to 30 Gbps as given here in the FAQ. It scales out automatically based on CPU usage and throughput. This will also ensure that the Firewall does not exceed its throughput from time to time resulting in keeping the Firewall healthy. Hope this helps.
Please let us know if you have any further questions/concerns and we will be glad to assist further.