# Certificates with a 2 node redundancy

**URL:** <https://forum.inductiveautomation.com/t/certificates-with-a-2-node-redundancy/102891>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [February 26, 2025, 10:01am UTC](https://forum.inductiveautomation.com/t/certificates-with-a-2-node-redundancy/102891 "2025-02-26T10:01:26Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Zied\_Brahmi](https://avatars.discourse-cdn.com/v4/letter/z/5daacb/32.png) [@Zied\_Brahmi](https://forum.inductiveautomation.com/u/Zied_Brahmi)\
**Post date:** [February 26, 2025, 10:01am UTC](https://forum.inductiveautomation.com/t/certificates-with-a-2-node-redundancy/102891/1 "2025-02-26T10:01:26Z")

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Hi,

We have a 2 node redundancy, and we updated some certificates for the main, however we did not for the backup, and now I see that the backup can't connect to some OPC UA server because of the client certificate that has not been updated and it's expired.

There is a way to sync both certificates? or do I need to create a certificate for the backup too?  
I m considering a force resync, but I m not sure about the behavior ( when I click force resync from the backup it will sync backup with master? or it will update the master with backup state? )  
Thank you.

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [February 26, 2025, 12:48pm UTC](https://forum.inductiveautomation.com/t/certificates-with-a-2-node-redundancy/102891/2 "2025-02-26T12:48:53Z")

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> [@Zied\_Brahmi](#):
>
> I need to create a certificate for the backup too?

Yes.

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<div class="post-metadata">

**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\
**Post date:** [February 26, 2025, 2:44pm UTC](https://forum.inductiveautomation.com/t/certificates-with-a-2-node-redundancy/102891/3 "2025-02-26T14:44:36Z")

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I thought the only things you could edit/change on a backup node were the redundancy settings and everything else sync'd.

The one thing I know it won't even allow it to sync without though are modules. If there's a mismatch of installed modules, they both have to have the same modules and versions installed, but otherwise I thought configuration including certificates were sync'd.

A force re-sync should force a resync from master to backup. (Or at least active to standby if for some reason your backup node is active).