In a wireless mesh deployment, multiple APs (with or without connections to wired Ethernet) communicate over wireless interfaces to form a single network. Each AP develops a list of neighboring devices and exchanges information with the rest of the network to form routes through the network. When a Meraki AP is connected to a wired Ethernet connection and obtains an IP address (either through static IP configuration or DHCP), the AP takes the identity of a “mesh gateway”. If an AP is not connected to a wired Ethernet connection or does not obtain an IP address over that connection, the AP operates as a “mesh repeater”, which relays wireless traffic through the mesh network, either to a gateway or through other repeaters.
Meraki devices in a mesh network configuration communicate using a proprietary routing protocol designed by Meraki. The protocol is designed specifically for wireless mesh networking, and accounts for several unique characteristics of wireless networks including variable link quality caused by noise or multi-path interference, as well as the performance impact of routing traffic through multiple hops. The protocol is also designed to provide ease of deployment and rapid convergence while maintaining low channel overhead.
Occasionally, a mesh repeater in the network will become unavailable, due to disconnection or changes in the environment. Each AP in the Meraki mesh network constantly updates its routing tables with the optimal path to the network gateways. If the best path changes due to node failure or route metric, traffic will flow via the best known path.
In the event of a mesh gateway failure or the emergence of a new mesh gateway with a better routing metric, all new traffic flows will be routed to the new mesh gateway. Because certain mesh gateways may be located on different IP subnets from each other, each TCP flow is mapped to a particular mesh gateway to avoid breaking established connections. The route through the network to the specified mesh gateway may change over time, to adapt to network conditions.