The web console in the master node cannot be accessed should that become the passive node in the event of a failover. However, the web console can be accessed when the slave node is in passive mode.

The embedded web server will not get initialised when the master node becomes the passive broker instance following a failover event. (allow-failback must be set to false in the slave instance.) 

t1. Master - Live: web console can be accessed
t2. Slave - Backup: web console can be accessed
t3. Kill the master broker 
t4. Start the master broker
t5. The master broker becomes passive: Unable to access the web console