If you have the console with you, visit ps3toolset.com on the PS3's web browser, wait for it to initialise and once everything's loaded go to the System Manager tab. If it's compatible there'll be a green check mark at the top of the page, and then you're good to go from there.
If you don't have it, then it's a little trickier. A 2511A model I would imagine has either 3.56 or 3.60 factory firmware, so it's a coin toss I would say. 3.56 factory firmware is the absolute maximum version that CFW is compatible with.