Removing The Rsa Host Keys And Zeroizing Storage; Configuring When To Re-Generate An Ssh Key - Dell S6100 Configuration Manual

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.
Other SSH related command include:
• crypto key generate : generate keys for the SSH server.
• debug ip ssh : enables collecting SSH debug information.
• ip scp topdir : identify a location for files used in secure copy transfer.
• ip ssh authentication-retries : configure the maximum number of attempts that should be used to authenticate a user.
• ip ssh connection-rate-limit : configure the maximum number of incoming SSH connections per minute.
• ip ssh hostbased-authentication enable : enable host-based authentication for the SSHv2 server.
• ip ssh key-size : configure the size of the server-generated RSA SSHv1 key.
• ip ssh password-authentication enable : enable password authentication for the SSH server.
• ip ssh pub-key-file : specify the file the host-based authentication uses.
• ip ssh rhostsfile : specify the rhost file the host-based authorization uses.
• ip ssh rsa-authentication enable : enable RSA authentication for the SSHv2 server.
• ip ssh rsa-authentication : add keys for the RSA authentication.
• show crypto : display the public part of the SSH host-keys.
• show ip ssh client-pub-keys : display the client public keys used in host-based authentication.
• show ip ssh rsa-authentication : display the authorized-keys for the RSA authentication.
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.
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