# Computer setup and configuration failure: unknown host

**URL:** <https://aiida.discourse.group/t/computer-setup-and-configuration-failure-unknown-host/399>\
**Category:** General Usage\
**Tags:** question, aiida\
**Created:** [May 28, 2024, 9:31am UTC](https://aiida.discourse.group/t/computer-setup-and-configuration-failure-unknown-host/399 "2024-05-28T09:31:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![vdemestral](https://yyz2.discourse-cdn.com/free1/user_avatar/aiida.discourse.group/vdemestral/32/121_2.png) [@vdemestral](https://aiida.discourse.group/u/vdemestral)\
**Post date:** [May 28, 2024, 9:31am UTC](https://aiida.discourse.group/t/computer-setup-and-configuration-failure-unknown-host/399/1 "2024-05-28T09:31:23Z")

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I would like to setup and configure a new remote computer (ssh-connection), but `verdi computer test computer_host_name` does not succeed. It seems that new computer host is not recognized.  
Details: I am using tcsh on AlmaLinux 8  
What can I do?

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**Author:** ![mbercx](https://yyz2.discourse-cdn.com/free1/user_avatar/aiida.discourse.group/mbercx/32/345_2.png) [@mbercx](https://aiida.discourse.group/u/mbercx)\
**Post date:** [May 28, 2024, 10:01am UTC](https://aiida.discourse.group/t/computer-setup-and-configuration-failure-unknown-host/399/2 "2024-05-28T10:01:50Z")

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Thanks for reposting here @vdemestral! We looked at this together and paramiko was giving an error related to the host not being in the `known_hosts` file. Typically when I connect to a remote machine with `ssh`, the host is automatically added to the `known_hosts` file after I confirm that this is fine. Since this wasn’t happening, I tried to add the host to the `known_hosts` using `ssh-keyscan` as also detailed here:

> <https://superuser.com/questions/1380591/ssh-how-to-add-host-to-ssh-known-host-file/1801679#1801679>

But alas, that command returned nothing for the host @vdemestral was trying to connect to. Not sure why.

In the end I suggested to change the key policy of the ssh configuration of the computer to use `AutoAddPolicy`:

```auto
  --key-policy [RejectPolicy|WarningPolicy|AutoAddPolicy]
                                  SSH key policy if host is not known.

```

And that did the trick. If anyone has other suggestions feel free to add them here!

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/aiida/original/1X/c417197d3750949351575d03ed03f5e2ad32e649.png) [@system](https://aiida.discourse.group/u/system)\
**Post date:** [May 28, 2026, 10:02am UTC](https://aiida.discourse.group/t/computer-setup-and-configuration-failure-unknown-host/399/3 "2026-05-28T10:02:46Z")

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