Technical Tip: Backup via SCP getting error - subsystem request failed on channel 0

[JNDias]

Description

This article describes the case when the backup via SCP got an error 'subsystem request failed on channel 0'.

Starting with OpenSSH 9.0, the scp command uses the sftp protocol by default. This may cause issues with current systems.

Source: https://www.openssh.com/releasenotes.html.

LINUX:~# scp admin@10.0.0.254:fgt-config config
subsystem request failed on channel 0
scp: Connection closed

Scope

Any FortiOS.

Solution

To solve this use the option -O flag to force openSSH to use the older SCP protocol at the client machine.

LINUX:~# scp -O admin@10.0.0.254:fgt-config config
fgt-config 100% 365KB 54.9KB/s 00:06

LINUX:~# ls -l
total 368
-rw------- 1 root root 373638 Feb 16 15:25 config

Related documents:

- Administration Guide -> Configuration backups

- Technical Tip: How to download a FortiGate configuration file and upload firmware file using secure ...