Description |
This article describes how to address an issue where the FGSP recv_err counter increases in FortiGate clusters, which may indicate session synchronization errors. Although the increase in this counter may not immediately affect cluster performance, prolonged errors could lead to stability concerns.
This issue can impact session synchronization in clustered environments. |
Scope | FortiGate. |
Solution |
To check the FGSP recv_err, can run the below command: diagnose sys session sync
sync_ctx: sync_started=1, sync_tcp=1, sync_others=1,
To resolve the issue of increasing FGSP recv_err counters, configure identical session-sync-dev interfaces for all FortiGate members in the FGSP cluster. This ensures proper session synchronization, which will prevent the counter from increasing without causing an impact on traffic or session management.
Configure identical session-sync-dev interfaces by running the following commands:
config system standalone-cluster
It is required to use the same interface for session-sync-dev: For example, If two FortiGates in the FGSP cluster then configure them like this:
config system standalone-cluster
In FortiGate B:
config system standalone-cluster
Note: When FGSP peers are formed between standalone FortiGates, the session synchronization process is performed by the kernel with UDP encapsulation. When using an FGSP session synchronization interface, the synchronization process is also offloaded to the kernel, albeit more efficiently without the UDP encapsulation. Therefore, a fast, dedicated, and stable L2 connection is recommended for the session synchronization interface between the FGSP peers. For redundancy, multiple synchronization interfaces can be configured. The session synchronization interface or interfaces should always be the same on each FGSP peer.
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