Virtual server and http pool not accessible

Dear All,

I am new to F5 and just starting learning this technology. I purchased a training suite and practicing on F5 BIG-IP LTM v11.3 VE. On a VMware workstation, I installed 3 small linux machines as webservers (SliTaz). I also installed Ubuntu desktop which I converted to a router. My BIG-IP LTM has 3 interfaces, internal to the webservers, external to public access, and a management network. The Ubuntu desktop routes everything and I can successfully reach each and every interface, including the servers. I can also browse (http) to these webservers.

The problem:

At the beginning, I could not get the pool members up. From a post by Doodle_guy (Offline (Enabled) - The children pool member(s) are down), where he tweaked the http monitor, I managed to bring the pool up. now when I created the virtual server, I can see both the pool and its members all up. but when I try to access the virtual server from the external network, the access is failing. For the pool monitoring I am using a new http monitor (GET /\r\n\r\n) The reason I used that is the normal http did not work for me (GET /\r\n)

Any suggestions please. I am stuck at the moment and cannot proceed to follow the training.

Thank you,