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  • 1.  Juniper SRX Cluster Firewall Failover

    This message was posted by a user wishing to remain anonymous
    Posted 09-18-2025 14:07
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    This message was posted by a user wishing to remain anonymous

    Hi Community,

    Please find the attached image illustrating a sample high availability (HA) architecture using Juniper firewalls(SRX 345) across two sites.

    Architecture Overview:

    • Two sites (Site-1 and Site-2), each with a pair of Juniper firewalls (SRX 345) configured in Active/Standby HA clusters.

    • Site-1 Active Firewall is connected directly to the Site-2 Active Firewall.

    • Site-1 Standby Firewall is connected directly to the Site-2 Standby Firewall.

    • Both HA pairs use interface monitoring for failover.

    Observed Behavior:

    • When a connectivity failure occurs between the Active Firewall and its local switch (e.g., link down at Site-1), the local HA pair correctly triggers a failover (Site-1 Standby becomes Active).

    • However, the corresponding firewall at the remote site (e.g., Site-2) does not perform a failover in sync, and continues operating with the previously active unit.

    Request:

    Could anyone advise how to ensure that a failover at one site also triggers a synchronized failover at the other site, maintaining traffic flow consistency across both ends?

    Any recommendations for best practices, configuration examples, or HA synchronization mechanisms would be greatly appreciated.

    Juniper SRX 345


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  • 2.  RE: Juniper SRX Cluster Firewall Failover

    Posted 09-26-2025 08:28

    Honestly, this design could be better. Firewalls at one end should not have a failover in concert with firewall at the other end

    Will your firewalls support MNHA ? presume not as these are low end. 

    Are the site-to-site links Layer 2 ?

    typically, some switching on the outside will help you, try to create  a "outside" VLAN on the switches you already have 



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