Why Errors Can Occur When Adding A Server; Potential Hazards When Blocking Traffic To And From Servers - 3Com 3C15500 - Network Director User Manual

Why Errors Can Occur
When Adding a
Server
Potential Hazards
When Blocking Traffic
To and From Servers
When you are adding a server it is necessary to enter a unique non-blank
name and either a valid DNS name or a valid IP address. If you choose to
enter an IP address it must not be a broadcast IP address. If any of these
conditions are not met then the wizard will not allow the server to be
added and an appropriate warning message will be displayed.
3Com Network Director will resolve DNS names by using the DNS servers
that the PC it is running on is configured to use and that 3Com Network
Director was able to contact when it was started. This means that you will
be unable to add servers by DNS name if any of the following occur:
3Com Network Director was unable to contact any of the configured
DNS servers when it was started.
3Com Network Director was only able to contact some of the
configured DNS servers when it was started and none of the DNS
servers contacted are able to resolve the DNS name.
It is not possible to contact any of the configured DNS servers while
you were adding servers.
It is only possible to contact some of the configured DNS servers while
you were adding servers and none of the DNS servers that can be
contacted are able to resolve the DNS name.
If it was not possible to contact a DNS server when 3Com Network
Director was started but you are now able to do so, you will need to
restart 3Com Network Director before it will use the DNS server.
Blocking traffic to and from servers is a powerful feature that prevents
access to particular resources. However, if you select the wrong servers to
be blocked then this can cause severe problems on your network.
Whenever you attempt to block traffic to and from a server it is important
that you check that:
The IP address of the server you wish to block does not belong to a
server that is critical to your network infrastructure, such as a DHCP or
RADIUS server. Blocking IP addresses such as these may prevent your
network infrastructure from functioning correctly.
Key Considerations 659