Inband Monitors

In this exercise, you need to limited the amount of monitor traffic to your back in servers. You will use the basic inband monitor, but you would like the servers to come up faster than default of 5 minutes. You will combine Inband and Active monitors to accomplish this.

Create an Inband monitor and Active monitor with an Up Interval

Create an inband monitor named my_inband. Use all the defaults.

Note the 300 second retry timer, after 3 failures in a 30 second period the BIG-IP will mark the member down and will not check the member again for 5 minutes.

Create a new custom monitor as the active monitor. Make the monitor an http monitor called active_http, with an Up Interval of 60 seconds and a Time Until Up of 30 second.

Assign the Inband monitor to a pool and test

You are going to begin by removing the current monitors for the www_pool and replacing them with the my_inband monitor only.

Go to the www_pool and remove all monitors and Update. Your pool members show now be Unchecked.

Q1. What is the status of the www_pool and www_vs configuration objects? Is the web site accessible? Why?

Add the my_inband monitor to the www_pool.

Q2. What are the status of www_pool and www_vs? Can you access the web site?

Let’s simulate a failure. Open a new browser tab to https://10.1.1.252:10000 this will bring you to Webmin on the back-end server:

Username: root
Password: default

Under Servers on the side-bar, select the Apache Webserver link. In the upper right corner select the Stop Apache link. This will effectively bring the web sites down.

Go to your pool statistics. After 30 seconds what is the status of the secure_pool and www_pool?

Q3. Why is the www_pool still showing up?

Attempt to access http://10.1.10.100 and refresh several times.

Q4. What is the status of the www_pool now?

In the Webmin tab, in the upper right corner, select Start Apache.

Once Apache is started, refresh you pool statistics page. Then try to browse to http://10.1.10.100/

Q5. What are the pool statuses and why?

It will be 300 seconds before the BIG-IP attempts to send any traffic to the offline pool members.

Go to the www_pool and add the active_http monitor to the pool.

Open a terminal window to BIG-IP and run the following tcpdump:

tcpdump -nni server_vlan -X -s0 port 80

Q6. How often to you see monitor traffic to the www_pool?

In the Webmin tab, Stop Apache again and attempt to browse http://10.1.10.100 and refresh several times. Check the status of your pools. The secure_pool and www_pool should be offline.

Q7. How often to you see monitor traffic to the www_pool?

In the Webmin tab Start Apache.

Q8. Did the www_pool come up within 30 seconds without client traffic? What did the tcpdump show?