Pros
Great salary when compared against other companies' internship programs. If you're working at the San Jose campus, you'll find many other college students scattered across the campus, as Cisco hires students from a variety of universities across the country. As other reviews have mentioned, the new hire program offers opportunities to meet with your peers. You will be working on pertinent projects with full-time employees, doing the same [if not similar] things they're doing. If your team is busy, you'll be busy too. There's an "open-door" culture at work - if you have questions or concerns, you are free to bring it up to your manager or co-workers. Many of them are more than willing to help you learn and contribute while you're here.
Cons
If you're not a local, relocating to San Jose can be confusing. Although Cisco offers relocation compensation, it'll be up to you to find a place to live for the next 3 to 6 months. "Corporate housing" is not offered for interns and co-ops. However, the Silicon Valley area has seen so many interns/temps that many neighborhoods/apartments offer short-term or month-to-month leases. This might not seem like a "con" (especially if you're a college student), but if your team needs you to stay until midnight to get something done, expect to do so (and expect overtime pay as well). Despite my short stay, I have definitely caught a whiff of the stagnating bureaucracy that can drive you, your project, and your co-workers nuts. But I suppose this is what happens in a "big company."