No way (the USB connection is for transferring files , it's not a network connection).
To connect your iLiad and your computer simultaneous to the internet
you have to use a router.
I suppose you have got the book edition without WIFI?
If so a router with integrated WIFI would be useless also.
Your "software update" was downloaded via the guest account at iRex,
to recognize your mac address you have to enter your account credentials
on the corresponding settings page of your iLiad and connect to IDS again
(using your travel hub).
HTH
Dirk
