How To Resolve TNDM Terminal Server Backup Error Caused by SSH2 Cipher Configuration


Issue

- Attempting to back up Terminal Servers using TNDB results in an error in the logs.

- Error message: `/config/ssh_config line 45: Bad SSH2 cipher spec 'aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc'. Couldn't read packet: Connection reset by peer. An error occurred. Configuration is not saved.`

- Other TNDB backups work correctly, but this specific backup process fails due to SSH2 cipher configuration errors and a connection reset.

Environment

- DIMETRA

- DIMETRA IP X-Core

- Network Transport

- TNDB version: 09.01.01.43 (2020.29184.0)

Resolution

1. Log into the Terminal Server:

1.1 Type `enable`.

1.2 Provide the password.

1.3 Execute the command: `configuration file transfer protocol tftp`.

2. Modify file transfer settings in TNDM:

2.1 Navigate to `File > Preferences`.

2.2 Change remote protocol preferences to Telnet and file transfer preferences to Not Secure.

3. Manually load the firmware from the extracted software package:

3.1 Extract the `.tar` file from the software package.

3.2 Point the firmware loading process to the extracted directory.

4. Perform the Terminal Server backup using the adjusted configuration.