hmmm...
And I assume you used to be able to access the network before?
I can't verify whether its with Blink due to me not using Blink.
So the problem may lie with the switch.
The funny thing though is that you were able to access the network and it randomly stopped working...
Firstly to isolate the problem: connect your blink connection, that is, the cable directly from your modem into the back to the PS3's ethernet port.
Go to network settings and select the easy option for the internet connection settings.
Try and see if it works.
Its supposed to work now, and this will verify the problem is not with Blink.
If it does not work, you'll need to get onto the Blink guys.
Hopefully one of the blink users on the forum will share what they know.
The other methods are:
On the PS3, go the system settings, and restore default system settings. (this will not erase anything on your system HDD)
When that is complete, go to network settings and set up your connection once more.
That is choose easy and wait for it to configure itself.
If it still does't work, manually enter an IP address for your PS3. That can be done by selecting manual instead of easy.
You will also need the switch configuration information. DNS etc..
Awaiting your feedback
Also whats your PSN ID?
So I can add you to the GATT PSN ID List located at:
http://www.carigamers.com/cms/forums/index.php/topic,10889.0.html