When the system is no longer able to resolve domains (ie. it's offline) you can let the HSMX gateway resolve all domains to one specific IP (resolve IP). This ensures that subscribers will no longer receive DNS time-outs.
To configure offline DNS browse to
Network→Network configuration→DNS settings (first tab). Tick
Enable offline mode and fill in the Resolve ip (unless the default value of 18.104.22.168 fits). The Resolve attempts variable sets the amount of failed DNS queries before the DNS resolver switches to offline mode. To avoid flapping and increase continuity, we recommend a value higher than two.
Tip: You could setup-an-offline-portal to show a predefined message ('gateway is offline') or keep your guests busy in the meantime with local information, flash games or the 'programme'.