Update virus base from LAN

Hello

I’m using CIS 4 on computers without internet connection. In configuration I added my host on lan (like http://192.****) when I have file bases.cav (from http://download.comodo.com/av/updates314/sigs/bases/bases.cav).
When i try update virus bases, I get an error message connection to the internet.

Does anyone know why?

Could you upload a screenshot of the issue!
Thanks

Regards
BlackList

bases.cav is in http://192.168.99.2/bases.cav
In a browser I can download file bases.cav, permision for this file - 777