Controller-less WLANs

Q:

How to configure the MTU on IAP uplink and tunnel interfaces? 

Instant 6.4.3.1-4.2.0.0 introduces the mtu command to support the configuration of Maximum Transmission Unit (MTU) size for bridge (br0) and cellular uplink interfaces. The mtu command can be used to configures the MTU size for tunnel and br0 interfaces, and uplink interfaces such as 3G/4G. The configured MTU size is applied when the uplink changes. 

Example: 

Instant-4.2 (config) # mtu ?
<size>     size

Instant-4.2 (config) # mtu 1200 ?
<cr>

The mtu command is not supported on pre 6.4.3.1-4.2.0.0 versions.