Why does SSH to IPv6 address not seem to work in pipeline?
Asked by Patrick Engelhardt:

According to <https://support.atlassian.com/bitbucket-cloud/docs/set-up-pipelines-ssh-keys-on-linux/#Update-the-known-hosts> I just need to input the IP of my remote host into the field and click "Fetch". However this does not seem work, the field stays empty and there is no report or error message why this fails. IPv4 worked fine for the same server.

Also when using the IPv6 inside the pipeline for SSH, it does not connect giving me an "Address not available". I tried to google this error and find any other reports or documentation that mentions IPv6 not being supported on Bitbucket for some reason. Running the command that Bitbucket does inside the Pipeline works fine on my machine. with IPv6 And again, IPv4 works fine from the Bitbucket pipeline as well.

The IPv6 is not formatted in any way and looks like *2001:0db8:85a3:8a2e::1* (not the actual IP). Adding \[\] around the IP broke it even further.

What is going on here? Is IPv6 simply not supported?


Answers:
author: elvagalex
body: I have the same problem. I have a dual-stack VM in GCP, and it is not possible to obtain the fingerprint from the Bitbucket UI using IPv6.

Additionally, addons within the pipeline such as \`atlassian/rsync-deploy\` or \`atlassian/ssh-run\` cannot be used; as a workaround I'm also have to switch to IPv4, but this address is dynamic, so I need to update the repository settings every time it changes on the VM.

Is there still no IPv6 support for pipelines on Bitbucket's infrastructure?


author: Syahrul
body: G'day, Patrick

As a start, is your server that pipeline tries to SSH into behind a firewall? If yes, have you checked and confirmed that the list of IPs available on our documentation below has been allowed:

[IP addresses to allowlist in your corporate firewall](https://support.atlassian.com/bitbucket-cloud/docs/what-are-the-bitbucket-cloud-ip-addresses-i-should-use-to-configure-my-corporate-firewall/)

Regards,  
Syahrul

comments: author: Patrick Engelhardt
body: Hi, seems that I closed the tab without actually sending the response the other day...

Yes, the server lies behind a firewall. This is properly configured though, which is demonstrated by us being able to connect from Bitbucket via SSH by using the IPv4 address, as well as from my personal machine using both protocols (IPv4 and IPv6). So I tend to rule out the firewall as the cause of our issue.

Any other ideas, what could cause this?

Kind regards,  
Patrick


author: Syahrul
body: Hi Patrick,

Can you please provide the reason for needing to connect with IPv6, along with the specific commands you are using and the complete error logs? This information would help me understand what you are trying to achieve and the specifics of the error.

Regards,  
Syahrul


author: Patrick Engelhardt
body: Dear Syahrul,

We are running a production environment on a cloud where IPv4 addresses cost extra.

I'm not running a command. I'm trying to add signature of the server using the IPv6 address to the known hosts which for some reason does not work as I stated in my first post. I do not know what the command is that is being ran here.

Connecting to the IPv6 address using the terminal works.

One thing I noticed is that the error message changed since the last time I tried to add the host to the known hosts using its IPv6 address. It is now "Unable to fetch fingerprints, check host SSH connection and try again". But again, I am able to connect to it so this alone doesn't tell me much.

Thanks for helping me with this! Since we have a workaround by using IPv4 I am also ok to leave this as unresolved and carry on.

Kind regards,  
Patrick


Tags: bitbucket-cloud

bitbucket-pipelines

cloud

ipv6