They're the creators of IOS, and in the past have acquired CatOS and switch tech from Catalyst and PIX from Phoenix Internet Exchange.
They are very well known for providing reliable hardware, excellent service, and will replace any hardware, any time, no questions asked, in less than 4 hours1?2?. They're also well known for not being cheap. However, if you are running a critical business operation on the InterNet, you can probably afford to pay for a box that will work constantly, consistently, and will never fail. In fact, you can pay for two, just in case something happens to the first one, and a redundant power supply that can run both machines if theirs fails.
They also provide high level networking qualifications that are recognised world wide:
(Where the 'CC' part stands for "Cisco Certified ...".)
In the Waikato it is possible to study for your CCNA and CCNP qualifications at WINTEC (Waikato Institute of Technology). Courses start at the beginning of each semester.
Christchurch Polytechnic also does Cisco certification courses.
Merely having a Cisco Certification doesn't mean that the holder can handle the jandel for real. Cisco experts and "Experts" are hard to separate.
While they have more market penetration in their market than MicrosoftCorporation have in theirs, they aren't considered to be abusing their monopoly by most people. As a recent vulnerability in IOS has shown, though, a MonoCulture still isn't necessarily a good thing.
1? They put out an apology just after Sept 11 2001, when all the planes were grounded and they were unable to meet this requirement. They've since fixed this so they are no longer dependent on planes.
2? Requires the purchase of a separate product called smartNet - which is a souped up warranty. Extras include forward-replacement and access to IOS upgrades. You don't need smartNet for a DSL firmware upgrade, but there is often a minimum IOS version required for firmware updates. smartNet is available with different response times for different costs, and can be restricted based on location (you can't get a 4 hour response in Ekatahuna)