Dell S4048-ON, Configuration Manual

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Troubleshooting SSH
To troubleshoot SSH, use the following information.
You may not bind
id_rsa.pub to RSA authentication while logged in via the console. In this case, this message displays:
%Error: No
username set for this term.
Enable host-based authentication on the server (Dell Networking system) and the client (Unix machine). The following message
appears if you attempt to log in via SSH and host-based is disabled on the client. In this case, verify that host-based authentication is
set to “Yes” in the
file ssh_config (root permission is required to edit this file):
permission denied (host based).
If the IP address in the RSA key does not match the IP address from which you attempt to log in, the following message appears. In
this case, verify that the name and IP address of the client is contained in the
file /etc/ hosts:
RSA Authentication Error
.
Telnet
To use Telnet with SSH, first enable SSH, as previously described.
By default, the Telnet daemon is enabled. If you want to disable the Telnet daemon, use the following command, or disable Telnet in
the startup config. To enable or disable the Telnet daemon, use the
[no] ip telnet server enable
command.
The Telnet server or client is VRF-aware. You can enable a Telnet server or client to listen to a specific VRF by using the
vrf vrf-
instance-name
parameter in the
telnet
command. This capability enables a Telent server or client to look up the correct
routing table and establish a connection.
Example of Using Telnet for Remote Login
Dell(conf)#ip telnet server enable
Dell(conf)#no ip telnet server enable
VTY Line and Access-Class Configuration
Various methods are available to restrict VTY access in Dell Networking OS. These depend on which authentication scheme you use
— line, local, or remote.
Table 80. VTY Access
Authentication Method VTY access-class support? Username access-class
support?
Remote authorization
support?
Line YES NO NO
Local NO YES NO
YES NO YES (with Dell Networking OS
version 5.2.1.0 and later)
RADIUS YES NO YES (with Dell Networking OS
version 6.1.1.0 and later)
Dell Networking OS provides several ways to configure access classes for VTY lines, including:
• VTY Line Local Authentication and Authorization
• VTY Line Remote Authentication and Authorization
VTY Line Local Authentication and Authorization
Dell Networking OS retrieves the access class from the local database.
To use this feature:
1. Create a username.
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