If you are getting an error saying your application gateway is not started or in failed state, then this will help you to kill your rest of the day
But there are few ways to start the App gateway rather than getting a new Gateway and connect the existing Backend Pools. I’m writing the Azure Resource explorer method which is easy to follow.
try this and if you still facing any issues let me know,
Once you into the App Gateway service you will notice that its in failed state. there isn’t any feature to start that.
Go into https://resources.azure.com
and login by using the same Azure credentials.
Then go into
Subscription > <Select the Subscription> > Providers > Resource Group > <Select the correct Resource Group> > Application Gateway > <Select the correct APP Gateway > >
You will notice that APP gateway is in failed state. There you can edit the state and then send a get command to change.
If you don’t have the permission then change the permission level to read write.
Or else go into the Action pane and click on start to enable the App Gateway.
No you can see that App Gateway status will change to updating and little later it will start and run without any issues.
Its simple like this and make sure to check the NICs attached into this. Sometime those also be in failed state. you can use the same resource Explorer to start them or change the private IP address into a another one and save. That will restart the VM and start the Network interface also.