If you still own PES 2011, you might want to upgrade as Konami will be shutting down its online servers for good.
The announcement was made on the official Pro Evolution Soccer twitter:
“Today we’re closing #PES 2011 online services. Thanks for all your support and remember you can still enjoy #PES 2012 and 2013 online.”
It appears that annually released sports games have an online lifespan of only two years. Although EA sometimes shuts down some of its servers after only 18 months.