Backup of Linux hosts stuck with authentication timeout

[toddehb]

Veeam case ID 06361112

Hi,

I am experiencing a strange behavior. My Veeam B&R is running on a local Server. On a remote site, connected via VPN, I am backing up a Ubuntu Server with installed Veeam Agent. On B&R I inserted correct Privkey and credentials. This has just worked fine till yesterday. At about the same time I was not able to ssh into that remote server anymore. After debugging that issue I discovered, that the solution was to at this

KexAlgorithms diffie-hellman-group18-sha512

to .ssh/config on my linux client on local site.

This is very strange, because that was not needed before and I don't see any changes either to client ssh config nor on server side.

My server config is like this:

Code: Select all

KexAlgorithms sntrup761x25519-sha512@openssh.com,curve25519-sha256,curve25519-sha256@libssh.org,gss-curve25519-sha256-,diffie-hellman-group16-sha512,gss-group16-sha512-,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha256
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
MACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com
HostKeyAlgorithms ssh-ed25519,ssh-ed25519-cert-v01@openssh.com,sk-ssh-ed25519@openssh.com,sk-ssh-ed25519-cert-v01@openssh.com,rsa-sha2-512,rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256,rsa-sha2-256-cert-v01@openssh.com

Then I checked the requirements of B&R at this https://helpcenter.veeam.com/docs/backu ... mendations

It looks to me that my server is fulfilling the requirement for Pubkey ssh .

I have no clue what is causing B&R to not connect to my Ubuntu server anymore.

[rovshan.pashayev]

Hello,

Are we sure that nothing was altered on VBR and Ubuntu side?
As you already submitted case, let's wait for support team's feedback first.

Rovshan

[toddehb]

I did not change anything.

[rovshan.pashayev]

Hello,

Please try to deploy new Ubuntu client machine and replicate similar backup jobs.
See the result differences, if you have not done it yet and you have enough resource for that.

Rovshan