Two important limitations exist with this feature, as currently implemented in 1.7.1:
(1) Unlike some implementations of this feature, there isn't a separate subnet defined for the guest network, the hosts are isolated using ebtables rules instead of using a separate subnet which means that the guest network shares the same range of IP addresses as the primary access point. The downside to this is that you can't match only guest-network IPs very easily with quotas/qos etc. Further releases will implement ways to match only the guest network in the Quotas and QoS sections but for now this is not possible.
(2) I don't recommend trying to use ap+client mode if you're going to enable the guest network. My experience is that it will work for a while and then become very unstable. I will investigate to see if there is a way to fix this, but I may disable enabling the guest network altogether when in ap+client mode.
In addition to guest network support, there are numerous bugfixes in this release, for issues identified in 1.7.0. Most of the minor (and one or two more major issues) that were identified after moving to the Barrier Breaker branch of OpenWRT have now been addressed.
New in 1.7.1:
- Guest Network Support
- Support for WAN connection via QMI
- Fixes several bugs preventing OpenVPN from working properly
- Fixes display of second 5GHz band SSID on Status/Overview page of dual band routers
- Fixes USB Printer Support
- Fixes Button Handlers
- Fixes 3G support by fixing test to determine whether 3G device exists
- Fixes issue with restarting minidlna
- Add citynetwork.se ddns provider
- Fixes issue with throttling hosts exceeding quotas being assigned the wrong QoS class