Fun F5 Troubleshooting
Test your HTTP keep alive from the F5 CLI:
Using curl:
curl -vvv -H "Host: domain.com" -H "Connection: Close" -H "User-Agent:" -H "Accept:" serverip:port/uripath.html
telnet serverip port
Then copy the first half of your keep alive
GET /uripath.html
From the above listed commands you should see exactly what the F5 is receiving when it sends a keep alive. From the returned http request you can determine the best data to use for a receive string.