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Access an ONTAP cluster using Telnet requests

Contributors netapp-barbe netapp-aaron-holt netapp-dbagwell netapp-sumathi netapp-aherbin
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You can issue Telnet requests to the cluster to perform administrative tasks. Telnet is disabled by default.

Telnet and RSH are not secure protocols; you should consider using SSH to access the cluster. SSH provides a secure remote shell and interactive network session. For more information, refer to Access the cluster using SSH.

Before you begin

The following conditions must be met before you can use Telnet to access the cluster:

  • You must have a cluster local user account that is configured to use Telnet as an access method.

    The -application parameter of the security login commands specifies the access method for a user account. Learn more about security login in the ONTAP command reference.

About this task

  • ONTAP supports a maximum of 50 concurrent Telnet sessions per node.

    If the cluster management LIF resides on the node, it shares this limit with the node management LIF.

    If the rate of in-coming connections is higher than 10 per second, the service is temporarily disabled for 60 seconds.

  • If you want to access the ONTAP CLI from a Windows host, you can use a third-party utility such as PuTTY.

  • RSH commands require advanced privileges.

ONTAP 9.10.1 or later
Steps

  1. Confirm that the Telnet security protocol is enabled:

    security protocol show

    1. If the Telnet security protocol is enabled, continue to the next step.

    2. If the Telnet security protocol is not enabled, use the following command to enable it:

      security protocol modify -application telnet -enabled true

    Learn more about security protocol show and security protocol modify in the ONTAP command reference.

  2. Confirm that the management-telnet-server service exists on the management LIFs:

    network interface show -services management-telnet-server

    Learn more about network interface show in the ONTAP command reference.

    1. If the management-telnet-server service exists, continue to the next step.

    2. If the management-telnet-server service does not exist, use the following command to add it:

      network interface service-policy add-service -vserver cluster1 -policy default-management -service management-telnet-server

      Learn more about network interface service-policy add-service in the ONTAP command reference.

ONTAP 9.9 or earlier
Before you begin

The following conditions must be met before you can use Telnet to access the cluster:

  • Telnet must already be enabled in the management firewall policy that is used by the cluster or node management LIFs so that Telnet requests can go through the firewall.

    By default, Telnet is disabled. The system services firewall policy show command with the -service telnet parameter displays whether Telnet has been enabled in a firewall policy. Learn more about system services firewall policy in the ONTAP command reference.

  • If you use IPv6 connections, IPv6 must already be configured and enabled on the cluster, and firewall policies must already be configured with IPv6 addresses.

    The network options ipv6 show command displays whether IPv6 is enabled. Learn more about network options ipv6 show in the ONTAP command reference. The system services firewall policy show command displays firewall policies.

Steps

  1. From an administration host, enter the following command:

    telnet hostname_or_IP

    hostname_or_IP is the host name or the IP address of the cluster management LIF or a node management LIF. Using the cluster management LIF is recommended. You can use an IPv4 or IPv6 address.

Example of a Telnet request

The following example shows how the user named "joe", who has been set up with Telnet access, can issue a Telnet request to access a cluster whose cluster management LIF is 10.72.137.28:

admin_host$ telnet 10.72.137.28

Data ONTAP
login: joe
Password:

cluster1::>