Next-Generation Firewall
Configure Active/Passive HA
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Next-Generation Firewall Docs
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- PAN-OS 12.1
- PAN-OS 11.2
- PAN-OS 11.1
- PAN-OS 11.0 (EoL)
- PAN-OS 10.2
- PAN-OS 10.1
- PAN-OS 10.0 (EoL)
- PAN-OS 9.1 (EoL)
- PAN-OS 9.0 (EoL)
- PAN-OS 8.1 (EoL)
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- PAN-OS 12.1
- PAN-OS 11.2
- PAN-OS 11.1
- PAN-OS 10.2
- PAN-OS 10.1
Configure Active/Passive HA
Learn how to configure active/passive HA pair of firewalls and HA.
Where Can I Use This? | What Do I Need? |
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For Strata Cloud Manager managed NGFWs:
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The following procedure shows how to configure a pair of firewalls in an
active/passive deployment as depicted in the following example topology.

Active/Passive High Availability (HA) provides firewall redundancy by maintaining two
firewalls in a primary-secondary relationship, where one firewall actively processes
traffic while the other remains in standby mode, ready to assume control if the
primary firewall fails. In an Active/Passive HA deployment, the active firewall
handles all network traffic and maintains the runtime state, while the passive
firewall continuously synchronizes its configuration and session information with
the active unit. When a failover event occurs—whether due to hardware failure,
software issues, or network connectivity problems—the passive firewall seamlessly
transitions to the active role, ensuring minimal service disruption and maintaining
network security policies. This configuration is ideal for environments that require
high availability but do not need the increased throughput that Active/Active HA
provides, making it a cost-effective solution for ensuring business continuity while
maintaining a single point of traffic processing.
Configure Active/Passive HA (PAN-OS)
Configure your firewalls in an active/passive high availability (HA) configuration
from PAN-OS and Panorama.
To configure an active/passive HA pair, first complete the following workflows on the
first firewall and then repeat the steps on the second firewall.
- Connect the HA ports to set up a physical connection between the firewalls.
- For firewalls with dedicated HA ports, use an Ethernet cable to connect the dedicated HA1 ports and the HA2 ports on peers. Use a crossover cable if the peers are directly connected to each other.
- For firewalls without dedicated HA ports, select two data interfaces for the HA2 link and the backup HA1 link. Then, use an Ethernet cable to connect these in-band HA interfaces across both firewalls.
Use the management port for the HA1 link and ensure that the management ports can connect to each other across your network.Enable ping on the management port.Enabling ping allows the management port to exchange heartbeat backup information.- Select DeviceSetupInterfacesManagement.Select Ping as a service that is permitted on the interface.If the firewall does not have dedicated HA ports, set up the data ports to function as HA ports.For firewalls with dedicated HA ports continue to the next step.
- Select NetworkInterfaces.Confirm that the link is up on the ports that you want to use.Select the interface and set Interface Type to HA.Set the Link Speed and Link Duplex settings, as appropriate.Set the HA mode and group ID.
- Select DeviceHigh AvailabilityGeneral and edit the Setup section.Set a Group ID and optionally a Description for the pair. The Group ID uniquely identifies each HA pair on your network. If you have multiple HA pairs that share the same broadcast domain you must set a unique Group ID for each pair.Set the mode to Active Passive.Set up the control link connection.This example shows an in-band port that is set to interface type HA.For firewalls that use the management port as the control link, the IP address information is automatically pre-populated.
- In DeviceHigh AvailabilityHA Communications, edit Control Link (HA1).Select the Port that you have cabled for use as the HA1 link.Set the IPv4/IPv6 Address and Netmask.If the HA1 interfaces are on separate subnets, enter the IP address of the Gateway. Do not add a gateway address if the firewalls are directly connected or are on the same VLAN.(Optional) Enable encryption for the control link connection.This is typically used to secure the link if the two firewalls are not directly connected, that is if the ports are connected to a switch or a router.
- Export the HA key from one firewall and import it into the peer firewall.
- Select DeviceCertificate ManagementCertificates.
- Select Export HA key. Save the HA key to a network location that the peer can access.
- On the peer firewall, select DeviceCertificate ManagementCertificates, and select Import HA key to browse to the location that you saved the key and import it in to the peer.
- Repeat this process on the second firewall to exchange HA keys on both devices.
Select DeviceHigh AvailabilityHA Communications, edit the Control Link (HA1) section.Select Encryption Enabled.If you enable encryption, after you finish configuring the HA firewalls, you can Refresh HA1 SSH Keys and Configure Key Options.Set up the backup control link connection.- In DeviceHigh AvailabilityHA Communications, edit Control Link (HA1 Backup).Select the HA1 backup interface and set the IPv4/IPv6 Address and Netmask.PA-3200 Series firewalls don’t support an IPv6 address for the HA1 backup control link; use an IPv4 address.Set up the data link connection (HA2) and the backup HA2 connection between the firewalls.
- In DeviceHigh AvailabilityHA Communications, edit the Data Link (HA2) section.Select the Port to use for the data link connection.Select the Transport method. The default is ethernet, and will work when the HA pair is connected directly or through a switch. If you need to route the data link traffic through the network, select IP or UDP as the transport mode.UPD is the only supported transport mode in Azure environments. UDP is the preferred transport mode for PA-1400 Series and PA-3400 Series firewalls.If you use IP or UDP as the transport method, enter the IPv4/IPv6 Address and Netmask.Verify that Enable Session Synchronization is selected.Select HA2 Keep-alive to enable monitoring on the HA2 data link between the HA peers. If a failure occurs based on the threshold that is set (default is 10000 ms), the defined action will occur. For active/passive configuration, a critical system log message is generated when an HA2 keep-alive failure occurs.You can configure the HA2 keep-alive option on both firewalls, or just one firewall in the HA pair. If the option is only enabled on one firewall, only that firewall will send the keep-alive messages. The other firewall will be notified if a failure occurs.Edit the Data Link (HA2 Backup) section, select the interface, and add the IPv4/IPv6 Address and Netmask.Enable heartbeat backup if your control link uses a dedicated HA port or an in-band port.You do not need to enable heartbeat backup if you are using the management port for the control link.
- In DeviceHigh AvailabilityGeneral, edit the Election Settings.Select Heartbeat Backup.To allow the heartbeats to be transmitted between the firewalls, you must verify that the management port across both peers can route to each other.Enabling heartbeat backup also allows you to prevent a split-brain situation. Split brain occurs when the HA1 link goes down causing the firewall to miss heartbeats, although the firewall is still functioning. In such a situation, each peer believes that the other is down and attempts to start services that are running, thereby causing a split brain. When the heartbeat backup link is enabled, split brain is prevented because redundant heartbeats and hello messages are transmitted over the management port.Set the device priority and enable preemption.This setting is only required if you wish to make sure that a specific firewall is the preferred active firewall. For information, see Device Priority and Preemption.
- In DeviceHigh AvailabilityGeneral, edit the Election Settings.Set the numerical value in Device Priority. Make sure to set a lower numerical value on the firewall that you want to assign a higher priority to.If both firewalls have the same device priority value, the firewall with the lowest MAC address on the HA1 control link will become the active firewall.Select Preemptive.You must enable preemptive on both the active firewall and the passive firewall.(Optional) Modify the HA Timers.By default, the HA timer profile is set to the Recommended profile and is suited for most HA deployments.
- In DeviceHigh AvailabilityGeneral, edit the Election Settings.Select the Aggressive profile for triggering failover faster; select Advanced to define custom values for triggering failover in your set up.To view the preset value for an individual timer included in a profile, select Advanced and click Load Recommended or Load Aggressive. The preset values for your hardware model will be displayed on screen.(Optional) Modify the link status of the HA ports on the passive firewall.The passive link state is shutdown, by default. After you enable HA, the link state for the HA ports on the active firewall will be green and those on the passive firewall will be down and display as red.Setting the link state to Auto allows for reducing the amount of time it takes for the passive firewall to take over when a failover occurs and it allows you to monitor the link state.To enable the link status on the passive firewall to stay up and reflect the cabling status on the physical interface:
- In DeviceHigh AvailabilityGeneral, edit the Active Passive Settings.Set the Passive Link State to Auto.The auto option decreases the amount of time it takes for the passive firewall to take over when a failover occurs.Although the interface displays green (as cabled and up) it continues to discard all traffic until a failover is triggered.When you modify the passive link state, make sure that the adjacent devices do not forward traffic to the passive firewall based only on the link status of the firewall.Enable HA.
- Select DeviceHigh AvailabilityGeneral and edit the Setup section.Select Enable HA.Select Enable Config Sync. This setting enables the synchronization of the configuration settings between the active and the passive firewall.Enter the IP address assigned to the control link of the peer in Peer HA1 IP Address.For firewalls without dedicated HA ports, if the peer uses the management port for the HA1 link, enter the management port IP address of the peer.Enter the Backup HA1 IP Address.(Optional) Enable LACP and LLDP Pre-Negotiation for Active/Passive HA for faster failover if your network uses LACP or LLDP.
- Ensure that in Step 12you set the link state to Auto.Select NetworkInterfacesEthernet.To enable LACP active pre-negotiation:
- Select an AE interface in a Layer 2 or Layer 3 deployment.
- Select the LACP tab.
- Select Enable in HA Passive State.
- Click OK.You cannot also select Same System MAC Address for Active-Passive HA because pre-negotiation requires unique interface MAC addresses on the active and passive firewalls.
To enable LACP passive pre-negotiation:- Select an Ethernet interface in a virtual wire deployment.
- Select the Advanced tab.
- Select the LACP tab.
- Select Enable in HA Passive State.
- Click OK.
To enable LLDP active pre-negotiation:- Select an Ethernet interface in a Layer 2, Layer 3, or virtual wire deployment.
- Select the Advanced tab.
- Select the LLDP tab.
- Select Enable in HA Passive State.
- Click OK.If you want to allow LLDP passive pre-negotiation for a virtual wire deployment, perform Step #id2351b088-8534-472b-9f43-34744c9075ec_idf8db2913-4497-4ed7-be0e-ef76451c55bd but do not enable LLDP itself.
Save your configuration changes.Click Commit.After you finish configuring both firewalls, verify that the firewalls are paired in active/passive HA.- Access the Dashboard on both firewalls, and view the High Availability widget.On the active firewall, click the Sync to peer link.Confirm that the firewalls are paired and synced, as shown as follows:
- On the passive firewall: the state of the local firewall should display passive and the Running Config should show as synchronized.
- On the active firewall: The state of the local firewall should display active and the Running Config should show as synchronized.
Configure Active/Passive HA (SCM)
Configure your firewalls in an active/passive high availability (HA) configuration from Strata Cloud Manager.This procedure assumes you already onboarded the firewalls you want to configure in an active/passive HA configuration to Strata Cloud Manager and have added them the same folder.- Log in to Strata Cloud Manager.Configure your HA Ethernet interfaces if you intend to use dedicated interfaces for the HA1 control links and HA2 data links.Select ManageConfigurationOverview and select the Folder Configuration Scope that the managed firewalls are associated with.Selecting the folder that the managed firewalls are associated with allows you to find and select the managed firewalls you want to configure in an active/passive HA configuration.In the HA Devices section, Create HA.Select the managed firewalls to configure in an active/passive HA configuration.
- Select Primary Device—Select the firewall to act as the primary active HA peer.
- Select Secondary Device—Select the firewall to act as the secondary passive HA peer.
Click Next to continue.Configure the HA1 Control Link Settings.The HA1 control link is used to exchange hellos, heartbeats, HA state information, and management plane synchronization for routing. This link is also used to synchronize configuration changes with its peer.- Configure the HA1 control link settings for the Primary Device.
- Select the Ethernet Port for the HA1 control link on the primary HA peer.
- Configure the IPv4 Address, Netmask, and Gateway of the HA1 control link for the primary HA peer.
- (Optional) Expand the Advanced Settings and enter the Monitor Hold Time (ms) that the firewall waits before declaring a peer failure due to a control link failure. Range is 1,000 to 60,000; default is 3,000.
Configure the HA1 control link settings for the Secondary Device.- Select the Ethernet Port for the HA1 control link on the secondary HA peer.
- Configure the IPv4 Address, Netmask, and Gateway of the HA1 control link for the secondary HA peer.
(Optional) Configure the HA1 Backup control link for both the Primary Device and Secondary Device.Configuring the HA1 Backup control link provides redundancy for the HA1 link. Consider the following guidelines when configuring back HA links.- The IP addresses of the primary and backup HA links must not overlap each other.
- HA backup links must be on a different subnet from the primary HA links.
- HA1-backup and HA2-backup ports must be configured on separate physical ports. The HA1-backup link uses port 28770 and 28260.
Click Next.Configure the HA2 Data Link Settings.The HA2 data link is used to synchronize sessions, forwarding tables, IPSec security associations, and ARP tables. Data flow on the HA2 link is always unidirectional except for the HA2 keep alive. It flows from the active or active-primary HA peer to the secondary or secondary-active HA peer. The HA2 link is a Layer 2 link.- Configure the HA2 data link settings for the Primary Device.
- Select the Ethernet Port for the HA2 data link on the primary HA peer.
- Configure the IPv4 Address, Netmask, and Gateway of the HA2 data link for the primary HA peer.
- (Optional) Expand the Advanced Settings and verify that Enable Session Synchronization is enabled.Enable session synchronization so that the secondary device has the session in its dataplane, which allows the firewall to match packets to the synchronized session and quickly forward packets. If you don’t enable session synchronization, the firewall must create the session again, which introduces latency and could drop connections.
- Select the Transport method.
- Layer2 transport via Ethernet—Use when the firewalls are connected back-to-back or through a switch (EtherType 0x7261).
- Layer3 transport via IP protocol 99—Use when Layer 3 transport is required (IP protocol number 99).
- Layer4 transport via UDP/29281—Use to take advantage of the fact that the checksum is calculated on the entire packet rather than just the header, as in the IP option (UDP port 29281). The benefit of using UDP mode is the presence of the UDP checksum to verify the integrity of a session sync message.
- (Best Practices) Enable and configure
HA2 Keep-alive to monitor the
health of the HA2 data link between the HA peers.
- Specify the Keep-alive
Action as Log
Only.Logs the failure of the HA2 interface in the system log as a critical event. Select this option for active/passive deployments because the active peer is the only firewall forwarding traffic. The passive peer is in a backup state and isn’t forwarding traffic; therefore a split datapath isn’t required. If you haven’t configured any HA2 Backup links, state synchronization will be turned off. If the HA2 path recovers, an informational log will be generated.
- Configure the Keep-alive Threshold (ms) to specify the duration in which keep-alive messages have failed before the Keep-alive Action is triggered. Range is 5,000 to 60,000; default is 10,000.
- Specify the Keep-alive
Action as Log
Only.
- Select the Transport method.
Configure the HA2 data link settings for the Secondary Device.- Select the Ethernet Port for the HA2 data link on the secondary HA peer.
- Configure the IPv4 Address, Netmask, and Gateway of the HA2 data link for the secondary HA peer.
(Optional) Configure the HA2 Backup data link for both the Primary Device and Secondary Device.When an HA2 backup link is configured, failover to the backup link will occur if there’s a physical link failure. With the HA2 keep-alive option enabled, the failover will also occur if the HA keep-alive messages fail based on the defined threshold.Click Next.Define HA Failover Conditions.Push Config to push your configuration changes.