How long is the warranty against rust on 2011 Chevrolet Silverado-1500?

There is no specific warranty against rust on a 2011 Chevrolet Silverado 1500. Chevrolet's warranties generally cover defects in materials and workmanship, not rust itself, which is considered normal wear and tear, especially considering environmental factors. Any rust issues would need to be assessed on a case-by-case basis to determine if it's covered under a general warranty (which would likely have expired) or if there was a specific manufacturing defect contributing to the premature rust.