Understanding FCoE and FIP Session High Availability
High availability features maintain storage network sessions when a system process is terminated and during certain types of upgrades:
High Availability for FIP Snooping
You can configure the system to perform FIP snooping on Ethernet interfaces that are connected to FCoE devices that have ENodes. The high availability function restores running FIP snooping sessions in case the Ethernet switching process is terminated.
QFX10000 switches do not support FIP snooping. You don’t need to enable FIP snooping on aggregation devices because FIP snooping is performed at the FCoE access edge.
The Ethernet switching process stores the FIP snooping state in a persistent storage module. If the Ethernet switching process terminates, the switch restores the existing FIP snooping sessions on the same interfaces that they were on before the Ethernet switching process terminated. The high availability features preserve:
Logged in ENodes
Discovered FCFs
Existing sessions
Existing FIP snooping filters
The complete restoration process, including reconciling all valid states, takes a maximum of 8 seconds. During the restoration process, the switch can learn a new FCF or a new FC switch, and new ENodes can log in to the FC network. However, FDISC messages from an ENode that is already logged in to the network might be dropped if the ENode has not yet been restored.
When the Ethernet switching process terminates ungracefully, the FIP keepalive timer is reset to the normal initial value, not the value at the time of the Ethernet switching process termination.
In the event of an Ethernet switching process termination, ENodes remain logged in, and existing sessions are not interrupted.
An Ethernet switching process restart and session restoration resets the FIP snooping statistics.