Service Manual

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 EMC 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.
Example of Using Telnet for Remote Login
DellEMC(conf)#ip telnet server enable
DellEMC(conf)#no ip telnet server enable
VTY Line and Access-Class Configuration
Various methods are available to restrict VTY access in . These depend on which authentication scheme you use — line, local, or
remote.
Table 101. VTY Access
Authentication Method VTY access-class support? Username access-class
support?
Remote authorization
support?
Line YES NO NO
Local NO YES NO
TACACS+ YES NO YES (with version 5.2.1.0 and
later)
RADIUS YES NO YES (with version 6.1.1.0 and
later)
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
retrieves the access class from the local database.
To use this feature:
1. Create a username.
2. Enter a password.
3. Assign an access class.
4. Enter a privilege level.
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Security