Cisco Nexus 5000 Series Switch CLI Software Configuration Guide (OL-16597-01, July 2009)

PurposeCommand or Action
Configures the use of the the MD5 or SHA-1 hash
algorithm.
switch(config)# fcsp dhchap hash [md5]
[sha1]
Step 2
Reverts to the factory default priority list of the
MD5 hash algorithm followed by the SHA-1 hash
algorithm.
switch(config)# no fcsp dhchap hash
sha1
Step 3
About the DHCHAP Group Settings
All Cisco Nexus 5000 Series switches support all DHCHAP groups specified in the standard: 0 (null DH
group, which does not perform the Diffie-Hellman exchange), 1, 2, 3, or 4.
If you change the DH group configuration, change it globally for all switches in the fabric.
Configuring the DHCHAP Group Settings
To change the DH group settings, perform this task:
Procedure
PurposeCommand or Action
Enters configuration mode.switch# configuration terminal
Step 1
Prioritizes the use of DH groups in the
configured order.
switch(config)# fcsp dhchap dhgroup [0 | 1
| 2 | 3 | 4]
Step 2
Reverts to the DHCHAP factory default order
of 0, 4, 1, 2, and 3.
switch(config)# no fcsp dhchap dhgroup [0
| 1 | 2| 3 | 4]
Step 3
About the DHCHAP Password
DHCHAP authentication in each direction requires a shared secret password between the connected devices.
To do this, you can use one of three configurations to manage passwords for all switches in the fabric that
participate in DHCHAP:
• Configuration 1—Use the same password for all switches in the fabric. This is the simplest configuration.
When you add a new switch, you use the same password to authenticate that switch in this fabric. It is
also the most vulnerable configuration if someone from the outside maliciously attempts to access any
one switch in the fabric.
• Configuration 2—Use a different password for each switch and maintain that password list in each
switch in the fabric. When you add a new switch, you create a new password list and update all switches
with the new list. Accessing one switch yields the password list for all switches in that fabric.
• Configuration 3—Use different passwords for different switches in the fabric. When you add a new
switch, multiple new passwords corresponding to each switch in the fabric must be generated and
configured in each switch. Even if one switch is compromised, the password of other switches are still
protected. This configuration requires considerable password maintenance by the user.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
630 OL-16597-01
Configuring FC-SP and DHCHAP
About the DHCHAP Group Settings