User guide

Key Considerations 187
■ The IP address of the server that you wish to block does not belong to
a server that is critical to your business, such as a database or email
server. Blocking IP addresses such as these may have a major impact
on your business.
■ The IP address of the server that you wish to block is not an IP address
that is served by a DHCP server. A device that has an IP address that is
served by a DHCP server can potentially change and this could lead to
intermittent problems for users of your network. If one or more of the
network infrastructure devices on your network obtained their
addresses via DHCP it could prevent your network from functioning
correctly.
If you have previously configured the network to block traffic to and from
a server it is important that prior to assigning an IP address to a new
device (or any existing device whose IP address you wish to change) you
check that the IP address that you are about to assign is not an IP address
of a server you have blocked. One way to check this is to run the
Prioritization Configuration report by selecting Tools > Reports and
examining the contents of the report for blocked servers.
If you accidently block an IP address then you can rectify this problem by
re-running the Prioritize Network Traffic Wizard and removing the server
from the list of servers to be blocked.
Servers That Cannot
be Selected for
Blocking
3Com Network Administrator prevents you selecting the following
servers for blocking:
■ The PC that is running 3Com Network Administrator. If you
attempted to block this server 3Com Network Administrator would no
longer be able to contact your network. This would prevent it from
configuring the devices on your network.
■ Any device in the device inventory that forms part of the network
infrastructure, such as a switch, hub or router.
3Com Network Administrator will not prevent you from blocking traffic
to and from a device that is not listed in the device inventory. If any of
your network infrastructure devices are not listed in the device inventory
you will need to check that you have not accidently selected one of these
devices for blocking before configuring traffic prioritization on your
network.
3Com Network Administrator for HP OpenView.book Page 187 Wednesday, November 12, 2003 2:33 PM