How do Instant APs work?

[sperez]

Hello

A customer of ours has asked us about the protocols behind Instant APs and their virtual controller technology.

I guess it works more or less like VRRP with no preemption and the same priority for all APs for the master AP election. For control traffic, i suppose it still uses PAPI tunnels but I would like to give our customer a more precise answer. Are there any tecnhnical notes addressing virtual controller technology?

Regards

Samuel

P.S. I've already seen the tech notes on the main webpage, but I'm afraid I need a bit more detail.

[sassy · Accepted solution]

The virtual controller or master is elected  using an election process that involves all IAPs in the group. If there is a contention, the IAP with the highest uptime will win.

There are no tunnels built for control traffic. The IAPs communicate using layer 2 broadcast and this is very lightweight.

There are additional details that can't be shared externally, but if there are specific questions or issues that the customer is concerned about, I will be happy to discuss those.

Thanks,

Shashi

[sperez]

Hello

We've been capturing traffic in one of our customers network and have found out the following:

• Control traffic (master AP election) between APs is done using PAPI (or at least it is UDP 8112) protocol.
• The configuration is passed from the master AP to the rest via HTTP (plain text)

[cdelarosa]

So the IAP works like the APs with the controller with bridge mode right?