How do we enable Automatic Signature updates on our F5 LTM 3600 11.3.0 (Build 3144.0)

Dear Team, How do we enable Automatic Signature updates on our F5 LTM 3600 11.3.0 (Build 3144.0) under Application Security : Attack Signatures : Attack Signatures Update

Our setup is like below: Our F5 LTM 3600 (10.10.x.x) is connected behind Juniper SRX Firewall which will communicate with Bluecoat SG Proxy on any port. On the other hand, Bluecoat Proxy will communicate with Internet on any port (80,443,53 etc). However when i click check for updates, it takes long time checking for updates and then ends with no result. Kindly let me know if there is a standard way to allow automatic updates of Signatures.

Thanks, Vishakh