Unable To Login To ACME Using Mac Terminal (SSH) client

Asset ID:	1-71-2383097.1
Update Date:	2018-04-09
Keywords:

Solution Type Technical Instruction Sure

Solution 2383097.1 : Unable To Login To ACME Using Mac Terminal (SSH) client

Applies to:

Acme Packet 3820 - Version S-Cx6.4.0 and later
Information in this document applies to any platform.

Goal

We are unable to login to ACME using terminal after the upgrade of macOS to High Sierra (10.13.2).

When we try to login via terminal using ssh we get the below error message:

ssh_dispatch_run_fatal: Connection to 192.168.xxx.xxx port 22: Invalid key length

Solution

This version of SSH based on OpenSSH 7.6 includes changes such that the minimum key-length should be at least 1024 bits.

Enterprise Software versions ECZ7.5.0 and later include a fix for this requirement.

Service Provider Software versions SCZ8.0.0 and later also include a fix for this requirement.

For earlier versions, there is a client side workaround that customers can implement until this can be resolved with longer SBC RSA keys, which is to
use the SBC's DSA public key instead.

Please add the following to the customer's ssh client ~/.ssh/config or /etc/ssh/ssh_config file:

Host 192.168.xxx.xxx
Ciphers aes256-cbc,aes192-cbc,aes128-cbc,3des-cbc
HostKeyAlgorithms=ssh-dss

Where "192.168.xxx.xxx" is the SBC's IP address

Attachments

This solution has no attachment