F5 Load balancer not working, but all the configurations are successful

Transactions are logged in /var/log/ltm

There are plenty of places we could start looking depending on the root cause.

First thing to consider is whether the frames are actually getting treatment from the VIP you think it is. I've seen folks get messed up by the processing order for instance https://support.f5.com/kb/en-us/solutions/public/9000/000/sol9038.html

You could try a "noisy" tcpdump; https://support.f5.com/kb/en-us/solutions/public/13000/600/sol13637.html

For you it would look something like;

tcpdump -ni 0.0:nnn "(host and port 80)" or "(host or host ...)" -s 0 -w

BIGIP adds a trailer that, when possible, tells you which VIP handled the frame. Of course, to make sense of it, you need that dissectors. You can grab those from; https://devcentral.f5.com/Wiki/AdvDesignConfig.F5WiresharkPlugin.ashx

Even without dissection, though the tcpdump will help you home in on the point of failure (are the frames even reaching F5? Can we see client-side counter-parts to these? etc) so maybe start there.

Cheers, Bernie