As a university wireless architect, I'm responsible for a number of remote sites as well as our main campus, with its 3,200 Cisco access points. Among these distant locations is the Syracuse University London Program (SULP), which features a 35-access-point WLAN and Meraki-enabled site-to-site VPN connection back to the mother ship in Syracuse. Users at SULP have a wireless experience that's identical to those on the main campus, right down to common SSID and authentication process. The cloud-managed Meraki framework in London is a good alternative to the far more complex and box-heavy Cisco option that would have been required to get the same functionality. I administer from afar and seldom have a concern about this far-flung part of campus.
To date, the managed wireless system has proven day in and day out to have been a great choice. Hundreds of happy users on the extended secure campus wireless network and statistically zero downtime are the proof in the network pudding, but at the same time Meraki has been thin in some important areas. For example, my high-dollar Cisco network is truly amazing at finding rogue APs and allowing me to make life miserable for the poor users behind them (if I so choose), while Meraki has simply done OK at showing the presence of unwanted network signals. Also, my Cisco wireless network offers a fairly robust wireless intrusion prevention/detection (WIPS/WIDS) capability, whereas the Meraki system does not. Until now.
In the newest Meraki code release, existing customers will soon get a free automatic upgrade that brings several welcome new features to the cloud-managed system console, including the Air Marshal security module. Air Marshal promises license-free (a differentiator) wireless intrusion, detection and threat mitigation. It all sounds very nice, with the ability to detect rogues and various wireless attacks with optional automatic response, but Meraki customers new to the security side of the WLAN need to proceed with caution.
To really make use of security features like WIPS/WIDS and rogue mitigation, admins need to have a policy that guides such things--and have strong faith in the vendor-provided dashboard that guides them. Developing a meaningful managed wireless security policy can be far more daunting than finding good hardware to enforce it, and a complicated dashboard can be a dangerous thing to uninitiated eyes. I like that signatures for attacks are "automatically updated," but I always wonder where the new attack vectors are coming from, and how many new wireless attacks are really being discovered on a regular basis. But then again, all it takes is one major attack to cripple the network and potentially lead to staff-terminating embarrassment for an organization, so arguably more capability in this area is always good (especially when licensing is free).
In practice, it's easy to say "we tolerate no rogues," while allowing automatic strafing of an area with disassociation frames to render the unauthorized access point useless takes things to a whole other level. I have personally made the mistake of shutting down a high-profile visitor's Mi-Fi device under our "no rogues" policy, and then had to answer for it even though I was abiding by our own rules (pretty much all environments end up needing exceptions on occasion).
Even informational rogue reporting is dicey. If I let my London Meraki environment email me every time a new "rogue" AP is seen by our Meraki APs, my inbox would be full of squawks from the hotels, businesses and apartments that surround our campus in very tight urban quarters. Adopting a proactive stance is far easier said than done in a world that's getting ever more saturated with wireless signals, and so these tools often get used in a more reactionary mode, after rogue-originated trouble arises.
There certainly is value in knowing what's afoot from the perspective of potentially malicious and policy-violating signals, so Meraki gets a thumbs up for Air Marshal. At the same time, how much time and effort a customer can put into using it, and how much value can really be extracted, will vary. This challenge is certainly not Meraki-specific, and any true enterprise-quality wireless system is expected to have tools the likes of Air Marshal, while the customer chooses how to make use of it.