Both BIG-IP devices in a pair are in an active state, processing traffic for different virtual servers or SNATs.
If one device fails over, the remaining device processes traffic from the failed device in addition to its own traffic.
Only one of the two BIG-IP devices is in an active state – that is, processing traffic – at any given time.
If the active device fails over, the second device enters active mode and processes traffic that was originally targeted for the primary device.
device service cluster
device service clusters
Device Service Clustering provides synchronization and failover of BIG-IP configuration data among multiple BIG-IP devices on a network.
You can configure a BIG-IP device on a network to synchronize some or all of its configuration data among several BIG-IP devices; fail over to one of many available devices; and/or mirror connections to a peer device to prevent interruption in service during failover.