# Guacamole in ONE7 with aarch servers

**URL:** <https://forum.opennebula.io/t/guacamole-in-one7-with-aarch-servers/14180>\
**Category:** Installation & Configuration\
**Created:** [August 14, 2025, 12:50pm UTC](https://forum.opennebula.io/t/guacamole-in-one7-with-aarch-servers/14180 "2025-08-14T12:50:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![tosaraja](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.opennebula.io/tosaraja/32/6686_2.png) [@tosaraja](https://forum.opennebula.io/u/tosaraja)\
**Post date:** [August 14, 2025, 12:50pm UTC](https://forum.opennebula.io/t/guacamole-in-one7-with-aarch-servers/14180/1 "2025-08-14T12:50:04Z")

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We’ve managed to get ONE7 up and running, and guacamole passes the desktop just fine from x86\_64 servers. But if the VM is running on an aarch / ARM64 host, guacamole just simply fails. Ideas why?

guacd and fireedge spit out these:

> guacd[586834]: Client has not defined its protocol version.  
> guacd[586834]: ConnectClientToTcpAddr6: connect  
> guacd[586834]: Unable to connect to VNC server  
> guacd[586834]: Unable to connect to VNC server.  
> guacd[586834]: User “@de0c4fa8-971e-4822-b3c8-e24a121e4e79” disconnected (0 users remain)
> 
> [info] Tunnel SSH created with PID: 602554 to connection: 58  
> [info] Closing unused ssh connection: 602554  
> Error: not opened  
> [error] WS connection closed: Error: not opened

* * *

**Versions of the related components and OS (frontend, hypervisors, VMs): ONE7 and hypervisors running Ubuntu 24.04.**

**Current results: VNC doesn’t work**

**Expected results: VNC works**

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<div class="post-metadata">

**Author:** ![tosaraja](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.opennebula.io/tosaraja/32/6686_2.png) [@tosaraja](https://forum.opennebula.io/u/tosaraja)\
**Post date:** [August 15, 2025, 5:28am UTC](https://forum.opennebula.io/t/guacamole-in-one7-with-aarch-servers/14180/2 "2025-08-15T05:28:43Z")

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Figured it out! The host was redeployed while testing different things, and it now had an offending ECDSA key and the SSH tunneling failed.

I just had to remove the entries from known hosts and all started working.

Man was this hard to debug and figure out…

I’d recommend OpenNebula did some checking of this and clearly prints the problem in logs.

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**Author:** ![system](https://canada1.discourse-cdn.com/flex031/uploads/opennebula/original/2X/1/14d66f1130b9cd292905f575da9b68a9f574dd03.png) [@system](https://forum.opennebula.io/u/system)\
**Post date:** [August 17, 2025, 5:29am UTC](https://forum.opennebula.io/t/guacamole-in-one7-with-aarch-servers/14180/3 "2025-08-17T05:29:08Z")

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