User's Manual

660 CHAPTER 15: PRIORITIZING NETWORK TRAFFIC
■ 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 e-mail
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 from the Reports dialog box, which is
launched 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 Director prevents you selecting the following servers for
blocking:
■ The PC that is running 3Com Network Director. If you attempted to
block this server 3Com Network Director would no longer be able to
contact your network. This would prevent it from configuring the
devices on your network.
■ Any device in the map that forms part of the network infrastructure,
such as a switch, hub or router.
3Com Network Director will not prevent you from blocking traffic to and
from a device that is not listed in the map. If any of your network
infrastructure devices are not listed in the map you will need to check
that you have not accidently selected one of these devices for blocking
before configuring traffic prioritization on your network.