Preventing users from accessing proxy

[duser]

Hello

I blocked access to proxy at all levels: Application, DNS, and web filter. But sometimes I find some users that were able to download many Gigabytes using proxy application as show in the screenshot (sent 981 MB/ received 6.68 GB).

What can I do to prevent that?  

[hmtay_FTNT]

Hello duser,

You need to set ISAKMP to Block. It will block all the IKE/IPsec connection which is commonly used by iOS VPNs. That log entry is a ISAKMP session. I will review the Peer2me signature. In any case, you have to set the ISAKMP signature to block.