Article Applies To:
Gen5: NSA E8510, E8500, E7500, NSA E6500, NSA E5500, NSA 5000, NSA 4500, NSA 3500,
NSA 2400, NSA 240, NSA 220, NSA 220W, NSA250, NSA250W.
TZ series: TZ 200, TZ 200 W, TZ 205, TZ 205 W, TZ 210, TZ 210 W.TZ 215, TZ215 Wireless
Gen4: PRO series: PRO 5060, PRO 4100, PRO 4060,PRO 3060, PRO 2040.
All Gen5 and Gen4 firmware versions (
Stateful HA is not supported for connections on which DPI-SSL is applied.
On TZ210 units the HA port/Interface must be
UNASSIGNED before setting up HA.
HA cannot be configured if
built-in wireless is enabled, the following warning will be displayed.
HA cannot be configured if PortShield is enabled, the following warning will be displayed.
Step 1: Stateful High Availability Cabling Example
The LAN (X0) interfaces are connected to a switch on the
LAN network. The WAN (X1) interfaces are connected to another switch,
which connects to the Internet.
The dedicated HA interfaces (Gen5) - or the last available copper ethernet interfaces, like X5 on Gen4 Pro models -
are connected directly to each other using a crossover cable.
you are connecting the Primary and Backup appliances to an Ethernet
switch that uses the spanning tree protocol, please be aware that it may
be necessary to adjust the link activation time on the switch port that
the SonicWALL interfaces connect to. For example, on a Cisco
Catalyst-series switch, it is necessary to activate spanning tree port
fast for each port connecting to the SonicWALL security appliance’s
Step 2: “Stateful and Non-Stateful High Availability Prerequisites” refer KBID 6238
Step 3: “Associating Appliances on MySonicWALL for High Availability”
Associating an Appliance at First Registration" refer KBID 6233
“Associating Pre-Registered Appliances” refer
“Associating a New Unit to a Pre-Registered Appliance” refer
“Removing an HA Association” refer
• “Replacing a SonicWALL Security Appliance” refer KBID 6231
Configuring High Availability (HA) in SonicOS Enhanced
The first task in setting up High Availability after initial setup is configuring the
High Availability > Settings
page on the Primary SonicWALL security appliance. Once you configure
High Availability on the Primary SonicWALL security appliance, you push
out the settings to the Backup SonicWALL security appliance. To
configure High Availability on the Primary SonicWALL, perform the
Step 1: Login to the SonicWALL Management Interface and in the left navigation pane, click
High Availability > Settings.
Step 2: Select the
Enable High Availability checkbox.
Step 3: Under
SonicWALL Address Settings,
type in the serial number for the Backup SonicWALL appliance. You can
find the serial number on the back of the SonicWALL security appliance,
or in the
System > Status screen of the Backup unit. The serial number for the Primary SonicWALL is automatically populated.
Step 4: Click
Accept to retain these settings.
Configuring Advanced High Availability Settings
Step 1: In the left navigation pane, click
High Availability > Advanced.
Step 2: To configure Stateful High Availability, navigate to the
Availability > Advanced screen and select
Enable Stateful Synchronization. A dialog box is displayed with recommended settings for the
Heartbeat Interval and
Probe Interval fields.
Note: Stateful High Availablility is not supported for connections on which DPI-SSL feature is applied.
The settings it shows are minimum recommended values. Lower values may
cause unnecessary failovers, especially when the SonicWALL is under a
heavy load. You can use higher values if your SonicWALL handles a lot of
When Stateful High Availability is not enabled, session
state is not synchronized between the Primary and Backup SonicWALL
security appliances. If a failover occurs, any session that had been
active at the time of failover needs to be renegotiated.
Step 3: Click
OK in the dialog box.
Step 4: If not using Stateful HA Failover, select
Enable Preempt Mode.
This feature controls the behavior in which the Primary unit will seize
the Active role from the Backup after it recovers from an error
condition, reboot or firmware upgrade, after it successfully
communicates to the backup unit that it is in a verified operational
Preempt mode is not recommended when enabling Stateful
High Availability, because preempt mode forces additonal
synchronizations of traffic, which is not recommended on high load
networks. In very early SonicOS versions for Gen5, such as v.18.104.22.168, the Preempt Mode checkbox could not be enabled with
Stateful High Availability
Step 5: To back up the firmware and settings when you upgrade the firmware version, select
Generate/Overwrite Backup Firmware and Settings When Upgrading Firmware.
Step 6: Select the
Enable Virtual MAC
checkbox. Virtual MAC allows the Primary and Backup appliances to share
a single MAC address. This greatly simplifies the process of updating
network routing tables when a failover occurs. Only the WAN or LAN
switch to which the two appliances are connected needs to be notified.
All outside devices will continue to route to the single shared MAC
Step 7: Optionally adjust the
to control how often the two units communicate. The default is 5000
milliseconds; the minimum recommended value is 1000 milliseconds. Less
than this may cause unnecessary failovers, especially when the SonicWALL
is under a heavy load.
Step 8: Set the
for the interval in seconds between communication with upstream or
downstream probe targets. SonicWALL recommends that you set the interval
for at least 5 seconds. You can set the Probe IP address(es) on the
High Availability > Monitoring screen.
Step 9: Typically, SonicWALL recommends leaving the
Failover Trigger Level (missed heart beats),
Election Delay Time (seconds), and
Dynamic Route Hold-Down Time timers to their default settings. These timers can be tuned later as necessary for your specific network environment.
• Heartbeat Interval (seconds) – This
timer is the length of time between status checks. By default this timer
is set to 5 seconds; using a longer interval will result in the
SonicWALL taking more time to detect when/if failures have occurred.
• Failover Trigger Level (missed heart beats) –
This timer is the number of heartbeats the SonicWALL will miss before
failing over. By default, this time is set to 5 missed heart beats.This
timer is linked to the Heartbeat Interval timer – for example, if you
set the Heartbeat Interval to 10 seconds, and the Failover Trigger Level
timer to 5, it will be 50 seconds before the SonicWALL fails over.
• Probe Interval – This timer controls
the path monitoring speed. Path monitoring sends pings to specified IP
addresses to monitor that the network critical path is still reachable.
The default is 20 seconds, and the allowed range is from 5 to 255
• Election Delay Time – This timer
can be used to specify an amount of time the SonicWALL will wait to
consider an interface up and stable, and is useful when dealing with
switch ports that have a spanning-tree delay set.
• The Dynamic Route Hold-Down Time –
This setting is used when a failover occurs on a High Availability pair
that is using either RIP or OSPF dynamic routing. When a failover
Dynamic Route Hold-Down Time is the number of
seconds the newly-Active appliance keeps the dynamic routes it had
previously learned in its route table. During this time, the
newly-Active appliance relearns the dynamic routes in the network. When
Dynamic Route Hold-Down Time duration expires, it
deletes the old routes and implements the new routes it has learned from
RIP or OSPF. The default value is 45 seconds. In large or complex
networks, a larger value may improve network stability during a
Dynamic Route Hold-Down Time setting is displayed only when the
Advanced Routing option is selected on the
Network > Routing page.
Step 10: Select the
Include Certificates/Keys checkbox to have the appliances synchronize all certificates and keys.
Step 11: Click
Synchronize Settings to manually synchronize the settings between the Primary and Backup appliances. The Backup will reboot.
Step 12: Click
if you previously uploaded new firmware to your Primary unit while the
secondary unit was offline, and it is now online and ready to upgrade to
the new firmware.
Synchronize Firmware is typically
used after taking your secondary appliance offline while you test a new
firmware version on the Primary unit before upgrading both units to it.
Step 13: Click
Accept to retain the settings on this screen.
Configuring High Availability > Monitoring settings
On the High
Availability > Monitoring
page, you can configure unique management IP addresses for both units
in the HA Pair which allows you to log in to each unit independently for
Also you can configure
Logical/Probe IP address
for SonicWALL to monitor a reliable device on one or more of the
connected networks. Failure to periodically communicate with the device
by the Active unit in the HA Pair will trigger a failover to the Idle
unit. If neither unit in the HA Pair can connect to the device, no
action will be taken.
Primary IP Address and Backup IP Address fields must be configured with
independent IP addresses on a LAN interface, such as X0, (or a WAN
interface, such as X1, for probing on the WAN) to allow logical probing
to function correctly
Once you finish configuring the High Availability settings on the Primary SonicWALL security appliance and click the
button, the Primary will automatically synchronize the settings to the
Backup unit, causing the Backup to reboot. You do not need to click the
Synchronize Settings button in the
Later, when you click
it means that you are initiating a full manual synchronization and the
Backup will reboot after synchronizing the preferences. You should see a
HA Peer Firewall has been updated
message at the bottom of the management interface page. Note that the
regular Primary-initiated synchronization (automatic, not manual) is an
incremental sync, and does not cause the Backup to reboot.
Testing the configuration
To verify that Primary and Backup SonicWALL security
appliances are functioning correctly, wait a few minutes, then power off
the Primary SonicWALL device. The Backup SonicWALL security appliance
should quickly take over.
From your management workstation, test connectivity
through the Backup SonicWALL by accessing a site on the public Internet –
note that the Backup SonicWALL, when Active, assumes the complete
identity of the Primary, including its IP addresses and Ethernet MAC
Log into the Backup SonicWALL’s unique LAN IP address. The management interface should now display
Logged Into: Backup SonicWALL Status: (green ball) Active in the upper right corner. If all licenses are not already synchronized with the Primary unit, navigate to the
System > Licenses
page and register this SonicWALL security appliance on mysonicwall.com.
This allows the SonicWALL licensing server to synchronize the
Now, power the Primary SonicWALL back on, wait a few
minutes, then log back into the management interface. The management
interface should again display
Logged Into: Primary SonicWALL Status: (green ball) Active in the upper right corner.
If you are using the Monitor Interfaces feature,
experiment with disconnecting each monitored link to ensure that
everything is working correctly.
Successful High Availability synchronization is not logged, only failures are logged.
High Availability Test / wrench LED status: