Removing The Rsa Host Keys And Zeroizing Storage; Configuring When To Re-Generate An Ssh Key; Configuring The Ssh Server Key Exchange Algorithm - Dell Force10 Z9000 Configuration Manual

copy scp: flash:
Example of Using SCP to Copy from an SSH Server on Another Switch
The following example shows the use of SCP and SSH to copy a software image from one switch running SSH server on UDP port
99 to the local switch.
Dell#copy scp: flash:
Address or name of remote host []: 10.10.10.1
Port number of the server [22]: 99
Source file name []: test.cfg
User name to login remote host: admin
Password to login remote host:

Removing the RSA Host Keys and Zeroizing Storage

Use the crypto key zeroize rsa command to delete the host key pairs, both the public and private key information for RSA 1
and or RSA 2 types. Note that when FIPS mode is enabled there is no RSA 1 key pair. Any memory currently holding these keys is
zeroized (written over with zeroes) and the NVRAM location where the keys are stored for persistence across reboots is also
zeroized.
To remove the generated RSA host keys and zeroize the key storage location, use the crypto key zeroize rsa command in
CONFIGURATION mode.
Dell(conf)#crypto key zeroize rsa

Configuring When to Re-generate an SSH Key

You can configure the time-based or volume-based rekey threshold for an SSH session. If both threshold types are configured, the
session rekeys when either one of the thresholds is reached.
To configure the time or volume rekey threshold at which to re-generate the SSH key during an SSH session, use the ip ssh
rekey [time rekey-interval] [volume rekey-limit] command. CONFIGURATION mode.
Configure the following parameters:
• rekey-interval: time-based rekey threshold for an SSH session. The range is from 10 to 1440 minutes. The default is 60 minutes.
• rekey-limit: volume-based rekey threshold for an SSH session. The range is from 1 to 4096 to megabytes. The default is 1024
megabytes.
Examples
The following example configures the time-based rekey threshold for an SSH session to 30 minutes.
Dell(conf)#ip ssh rekey time 30
The following example configures the volume-based rekey threshold for an SSH session to 4096 megabytes.
Dell(conf)#ip ssh rekey volume 4096

Configuring the SSH Server Key Exchange Algorithm

To configure the key exchange algorithm for the SSH server, use the ip ssh server kex key-exchange-algorithm
command in CONFIGURATION mode.
key-exchange-algorithm : Enter a space-delimited list of key exchange algorithms that will be used by the SSH server.
The following key exchange algorithms are available:
• diffie-hellman-group-exchange-sha1
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