Dell SuperMassive 9200 Getting Started Manual page 41

Configuring Optional HA Settings
The following settings are optional. You can configure these
settings from the High Availability > Settings page.
1. To backup the firmware and settings when you upgrade the
firmware version, select the Generate/Overwrite Backup
Firmware and Settings When Upgrading Firmware
checkbox.
2. Select the Enable Virtual MAC checkbox to allow the
Primary and Secondary appliances to share a single MAC
address. This greatly simplifies the process of updating
network ARP tables and caches when a failover occurs.
Only the WAN switch that the two appliances are
connected to needs to be notified. All outside devices will
continue to route to the single shared MAC address.
3. Click Apply to save any of the settings on this page.
Configuring HA Advanced Settings
The following settings are optional. You can configure the
following settings from the High Availability > Advanced
page.
1. Adjust the Heartbeat Interval to control how often the two
units communicate. The default and recommended
minimum is 1000 milliseconds.
2. The Failover Trigger Level sets the number of heartbeats
that can be missed before failing over. Dell SonicWALL
recommends leaving this field at its default setting, and
tuning later if needed.
40 | Configuring a Stateful HA Pair
3. Set the Probe Interval for the interval in seconds between
communication with upstream or downstream systems.
The recommended setting is an interval of at least 5
seconds. You can set the Probe IP Address(es) on the
High Availability > Monitoring screen.
4. Set the Probe Count, which is the number of consecutive
probes before the appliance considers the network path
unreachable or broken. The default count is 3.
5. The Election Delay Time is the number of seconds
allowed for internal processing between the two units in the
HA pair before one of them takes the primary role.
Dell SonicWALL recommends leaving this field at its
default setting, then tuning later if needed.
6. Enable the Active / Idle Failover only when ALL
aggregate links are down checkbox to treat the
aggregated link as down (causing a failover) only if all
member links are down.
7. Select the Include Certificates/Keys checkbox to have
the appliances synchronize all certificates and keys.
8. Click Synchronize Settings to synchronize the settings
between the Primary and Secondary appliances.
9. Click Synchronize Firmware if you previously uploaded
new firmware to your Primary appliance while the
Secondary appliance was offline.
10. Click Force Active / Idle Failover to force a failover
between your Primary and Secondary appliances.
11. Click Accept to retain the settings on this screen.