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Example of Client-Based SSH Authentication
DellEMC#ssh 10.16.127.201 ?
-c Encryption cipher to use (for v2 clients only)
-l User name option
-m HMAC algorithm to use (for v2 clients only)
-p SSH server port option (default 22)
-v SSH protocol version
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 le ssh_cong (root permission is required to edit this le): 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 le /etc/hosts: RSA Authentication Error.
Telnet
To use Telnet with SSH, rst 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 cong. 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 specic 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
DellEMC(conf)#ip telnet server enable
DellEMC(conf)#no ip telnet server enable
VTY Line and Access-Class Conguration
Various methods are available to restrict VTY access in . These depend on which authentication scheme you use — line, local, or remote.
Table 74. 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 congure access classes for VTY lines, including:
• VTY Line Local Authentication and Authorization
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