Not connected to the internet message appears

Hello,

Using Mac OS 10.7- Satellite dish to modem to computer, no router.

This problem is of recent origin.
While working online I frequently see the message "not connected to the internet". Then a second or so later it reconnects. I went to System Preferences - Network and watched "Ethernet" for a period of time. It would mostly show as "connected", but then momentarily show "disconnected - no IP address". This would be very brief and then it would show as "connected" again without me doing anything.


Could you give a possible cause and solution. Thanks.

Bill