Security Measures
153
Instruction Manual - NXA-ENET8-POE+
Configuring the SSH Server
Use the Security > SSH (Configure Global) page to enable the SSH server and configure basic settings for authentication.
NOTE:
You must generate DSA and RSA host keys before enabling the SSH server. See the Generating the Host Key Pair
.
The following table lists the options on this page:
Perform these steps to configure the SSH server:
1.
Click
Security
>
SSH
.
2.
Select
Configure Global
from the Step list.
3.
Enable the SSH server.
4.
Adjust the authentication parameters as required.
5.
Click
Apply
.
Generating the Host Key Pair
Use the Security > SSH (Configure Host Key - Generate) page to generate a host public/private key pair used to provide secure
communications between an SSH client and the switch. After generating this key pair, you must provide the host public key to SSH
clients and import the client's public key to the switch as described in the
NOTE:
A host key pair must be configured on the switch before you can enable the SSH server. See the Configuring the SSH
for more information.
The following table lists the options on this page:
Security - SSH Options
SSH Server Status
Allows you to enable/disable the SSH server on the switch. (Default: Disabled)
Version
The Secure Shell version number. Version 2.0 is displayed, but the switch supports management
access via either SSH Version 1.5 or 2.0 clients.
Authentication Timeout
Specifies the time interval in seconds that the SSH server waits for a response from a client during
an authentication attempt. (Range: 1-120 seconds; Default: 120 seconds)
Authentication Retries
Specifies the number of authentication attempts that a client is allowed before authentication fails
and the client has to restart the authentication process. (Range: 1-5 times; Default: 3)
Server-Key Size
Specifies the SSH server key size. (Range: 512-896 bits; Default:768)
• The server key is a private key that is never shared outside the switch.
• The host key is shared with the SSH client, and is fixed at 1024 bits.
FIG. 180
Configuring the SSH Server
Security - SSH Options
Host-Key Type
The key type used to generate the host key pair (i.e., public and private keys). (Range: RSA
(Version 1), DSA (Version 2), Both; Default: Both)
The SSH server uses RSA or DSA for key exchange when the client first establishes a connection
with the switch, and then negotiates with the client to select either DES (56-bit) or 3DES (168-bit)
for data encryption.
NOTE:
The switch uses only RSA Version 1 for SSHv1.5 clients and DSA Version 2 for SSHv2
clients.
Save
Saves the host key from RAM (i.e., volatile memory) to flash memory. Otherwise, the host key pair is
stored to RAM by default. Note that you must select this item from the Show page. (Default:
Disabled)