Administrator Guide

Table Of Contents
Managing General System Settings 395
Requesting the time from a unicast SNTP server is more secure. Use this
method if you know the IP address of the SNTP server on your network. If you
allow the switch to receive SNTP broadcasts, any clock synchronization
information is accepted, even if it has not been requested by the device. This
method is less secure than polling a specified SNTP server.
To increase security, authentication can be required between the configured
SNTP server and the SNTP client on the switch. Authentication is provided
by Message Digest 5 (MD5). MD5 verifies the integrity of the
communication and authenticates the origin of the communication.
What Configuration Is Required for Plug-In Modules?
The Dell Networking N3000/N4000 Series switches support several different
plug-in modules (also known as cards) for the expansion slots located on the
back of the switch. For information about the slots and the supported
modules, see "Hardware Overview " on page 99. The card type can be pre-
configured prior to inserting it into the switch.
Hot-swap is supported on the Dell Networking N3000/N4000 Series switch
modules.
Before inserting a new module into the expansion slot that was previously
occupied by a different type of module, issue a no slot command from the
CLI so that the switch can recognize the new module.
Once a module has been recognized by the switch, its configuration is stored
locally on the switch as the switch default. The module configuration appears
in the running-config for informational purposes.