What's the company culture like at Cisco?

Depends on the group and whether or not you are remote or in the office. Huge remote culture so sometimes those folks can feel isolated depending on the group. If you are in office, it depends on which. Such a large acquisition company that people are sometimes naturally segmented. And being so large, you don't always feel connected to the company itself but more so your team.

I believe are culture is really quite good but there persists some evolutionary slowness to move to more modern technologies and techniques

Open, friendly, supportive, demanding, fast, and top-down but changing

Open doors, provided there's no questioning