Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.1P1 - Page 788
Removing the RSA Host Keys and Zeroizing Storage, Configuring When to Re-generate an SSH Key,
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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 • diffie-hellman-group1-sha1 • diffie-hellman-group14-sha1 The default key exchange algorithms are the following: 788 Security
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