Pros
Cisco is a great place to balance work and everyday life or your side interests. Working from home is accepted, you can take a long lunch break and disappear for a few hours, nobody will notice. There is plenty of vacation and salary is decent compared to the work you are required to do. It's a big name in the networking business and if you are smart enough you can learn a lot. There are plenty of opportunities to learn with online and real classes.
Cons
The level and quality of engineering is overall pretty low, lower than many other companies: many people still use the same tools as they used 30 years ago. Other are jealous of what they know and try not to share it with anybody (job security?!?). Process is very very long and frustrating: with 60k employees, it sometimes takes a week to do a 1 hour job. It all explain why many products are coming from acquisitions and are not developed internally. There is no diversity at all in engineering: I would guess 90% is from India (maybe more). Also, from the level of director going up, many are "retired": they are just interested in getting their bonus and consider sending random emails at random hours (with their blackberry and similar) a valid proof that they are working around the clock. There are not many chances to improve your career once you get on board in term of salary or promotion: i.e., negotiate well before signing or you might just get stuck with something that you really do not like. Also, watch out on where you end up going: you might be forced to just do fire fighting and bug fixing and no development (almost at all): that's not good in your resume and it's not good for your mind.