# Bad Handshake errors after EKS upgrade

**URL:** <https://forums.suse.com/t/bad-handshake-errors-after-eks-upgrade/43111>\
**Category:** SUSE Rancher Prime\
**Created:** [May 8, 2024, 8:27am UTC](https://forums.suse.com/t/bad-handshake-errors-after-eks-upgrade/43111 "2024-05-08T08:27:58Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![mikeh89](https://sea2.discourse-cdn.com/flex022/user_avatar/forums.suse.com/mikeh89/32/9404_2.png) [@mikeh89](https://forums.suse.com/u/mikeh89)\
**Post date:** [May 8, 2024, 8:27am UTC](https://forums.suse.com/t/bad-handshake-errors-after-eks-upgrade/43111/1 "2024-05-08T08:27:58Z")

</div>

After upgrading K8s version on EKS to ‘v1.27.12-eks-adc7111’, the cluster agent fails to enter a ready state on the local Rancher cluster.

Checking the Rancher server logs, I see these errors:

```auto
2024/05/08 08:23:26 [ERROR] Failed to connect to peer wss://10.42.0.52/v3/connect [local ID=10.42.0.51]: websocket: bad handshake
2024/05/08 08:23:27 [ERROR] Failed to handle tunnel request from remote address 10.42.0.52:47634: response 400: cluster not found

```

On the EKS cluster, there are no obvious errors on the cattle-cluster-agent, nor the rancher-webhook

Any ideas what might be causing the 400 errors + bad handshake errors? Or advice on where to look? I’ve tried de-registering, removing the rancher-related namespaces and re-registering the EKS cluster, as this has helped in the past, but no luck there.

Rancher version: v2.8.3  
Running on k3s version: v1.28.8+k3s1   
EKS version: v1.27.12-eks-adc7111