Network OS Administration Guide

Supporting Network OS 6.0.1a

Part Number: 53-1003768-04

Telnet and SSH

Telnet and Secure Shell (SSH) are mechanisms for allowing secure access to management functions on a remote networking device. SSH provides a function similar to Telnet, but unlike Telnet, which offers no security, SSH provides a secure, encrypted connection to the device.

SSH and Telnet support is available in privileged EXEC mode on all Brocade VDX platforms. Both IPv4 and IPv6 addresses are supported.

Telnet and SSH services are enabled by default on the switch. When the Telnet server or SSH server is disabled, access to the switch is not allowed for inbound Telnet or SSH connections, thereby restricting remote access to the switch.

Network OS supports up to 32 CLI sessions on a switch.

In configuration mode, the CLI can be used to disable Telnet or SSH service on the switch. Doing so will terminate existing inbound Telnet or SSH connections and block any new inbound Telnet or SSH connections to the switch. Additional inbound Telnet or SSH connections will not be allowed until the Telnet server or SSH server is re-enabled. If you have admin privileges, you can re-enable inbound Telnet or SSH connections from configuration mode.

If you are in logical chassis cluster mode (refer to Operational modes), the command for enabling or disabling Telnet or SSH services is not distributed across the cluster. The RBridge ID of the node should be used to configure the service on individual nodes.

In operational mode, you can use the show command to display whether Telnet or SSH is enabled or disabled on the switch.

Telnet alone is not supported on the Brocade VDX 2740 or Brocade VDX 2746. Telnet port 23 is denied by default.