Exinda EXNV-10063, Administration Manual

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Exinda Network Orchestrator 3 Using | 331
Link State Mirroring
Even though High Availability protocols are usually handled by the Routers or Multi-Layer switches that act as the “next-
hops”, the core switches connected to them also need to detect a link failure in order for the entire network to converge
properly. When an Exinda appliance is located in the middle of the connection between a Switch and an HA router, and
the link between the HA router and the Exinda goes down, the remaining link (Exinda to Switch) will remain up,
avoiding the failure detection by the switch and creating convergence problems. In order to overcome this scenario, you
should use the Link State Mirroring feature.
When this option is enabled, the Exinda appliance brings down the second port of a bridge if the first port goes down.
This feature allows the Exinda appliance to sit between a WAN router and a switch without blocking detection of switch
outages by the router. This is a global setting that is applied to all enabled bridges. Exinda recommends to always enable
this setting when the appliance is configured in cluster mode, this option is located under
Configuration > System >
Network > NICs and is disabled by default:
NOTE
An Exinda Appliance goes into “bypass” mode by default if it is shut down. In an HA/Cluster environment, in order
to maintain control and visibility on the network, the administrator might want the entire traffic to failover to a
backup link if the Exinda appliance on the active one is offline. In order to do this, you need the appliance that went
offline to purposefully break the traffic so the HA protocol can hand it over to the backup link. To achieve this
functionality, modify the “On Failover” mode for the specific bridge to “NO LINK” mode (This option is located under
Configuration > System > Network > NICs):
Exinda recommends that you leave at least one of the cluster nodes in “Bypass” failover mode in case there is a
power failure that affects the entire cluster.
The “NO LINK” option is not available on the 3062 model. For the 4062 model, it is necessary to purchase an extra
Expansion Card given that the on-board bridges do not come with this feature.
To specify what data is synchronized between cluster members
[no] cluster sync {all|acceleration|monitor|optimizer|compression}
all
- Acceleration, monitor, optimizer data, and compression are synchronized. This is disabled by default.
acceleration
- Synchronize acceleration data only
monitor
- Synchronize monitor data only
optimizer
- Synchronize optimizer data only
compression
- Configure cluster compression settings including compression type and compression level.