H3C Technologies H3C S6300 Series Switches - Manual (Page 281)

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Configuring SSH
Overview
Secure Shell (SSH) is a network security protocol. Using encryption and authentication, SSH can
implement secure remote access and file transfer over an insecure network.
SSH uses the typical client-server model to establish a channel for secure data transfer based on TCP.
SSH includes two versions: SSH1.x and SSH2.0 (hereinafter referred to as SSH1 and SSH2), which are
not compatible. SSH2 is better than SSH1 in performance and security.
The device supports the following SSH applications:
• Secure Telnet—Stelnet provides secure and reliable network terminal access services. Through
Stelnet, a user can securely log in to a remote server. Stelnet can protect devices against attacks,
such as IP spoofing and plain text password interception. The device can act as an Stelnet server or
an Stelnet client.
• Secure File Transfer Protocol—Based on SSH2, SFTP uses SSH connections to provide secure file
transfer. The device can serve as an SFTP server, allowing a remote user to log in to the SFTP server
for secure file management and transfer. The device can also serve as an SFTP client, enabling a
user to log in from the device to a remote device for secure file transfer.
• Secure Copy—Based on SSH2, SCP offers a secure approach to copying files. The device can act
as an SCP server, allowing a user to log in to the device for file upload and download. The device
can also act as an SCP client, enabling a user to log in from the device to a remote device for secure
file transfer.
• NETCONF over SSH—Based on SSH2, it enables users to securely log in to the device through SSH
and perform NETCONF operations on the device through the NETCONF-over-SSH connections.
The device can act only as a NETCONF-over-SSH server. For more information about NETCONF,
see Network Management and Monitoring Configuration Guide.
When acting as an SSH client or server, the device supports the following SSH versions:
• When acting as an SSH client, the device supports only SSH2.
• When acting as an Stelnet, SFTP, or SCP server, the device supports both SSH2 and SSH1 in
non-FIPS mode and only SSH2 in FIPS mode.
• When acting as a NETCONF-over-SSH server, the device supports only SSH2 in either non-FIPS
mode or FIPS mode.
How SSH works
This section uses SSH2 as an example to list the stages involved in secure session establishment between
an SSH client and an SSH server. For more information about these stages, see SSH Technology White
Paper.