Instructions
Power up your PS3 and select "Network Settings" on the PS3 system settings page. This is located on the far left of the PS3 main menu.
Select "Connection Settings" and "Custom" for "DNS Server Settings." Locate the "Primary DNS" IP address on the next page.
Enter in "67.202.81.137" for the primary and verify your selection by pressing the "X" button. Select "Test Connection" on the next page to verify the new settings that you have changed.
Go back to the PS3 main menu and select your game from the game section. You can now play online without updating the PS3 software.