3Com 3C16111 - SuperStack 3 Firewall Web Site Filter, User Manual

Page: 64 / 214

64 C
HAPTER
4: B
ASIC
S
ETTINGS OF THE
F
IREWALL
To delete a binding, which frees the IP address in the DHCP server, select
the binding from the list and then click
Delete.
Using the Network
Diagnostic Tools
The Firewall has several tools built in which can help you solve network
problems. Click
Network, and then select the Diagnostics tab.
Figure 28 Diagnostics Window with Pull-down Menu
Choosing a
Diagnostic Tool
The drop-down box provides five diagnostic tools:
DNS Name Lookup
Domain Name Service (DNS) is an internet service which allows users to
enter an easily remembered host name, such as
www.3Com.com
, instead of
numerical IP addresses to access Internet resources. The Firewall has a
DNS Lookup tool that returns the numerical IP address of a host name.
1 Select DNS Name Lookup from the Choose a diagnostic tool menu.
2 Type the host name to lookup in the Look up the name box and click G o.
The Firewall then queries the DNS server and displays the result at the
bottom of the screen.
The IP address of at least one DNS Server must be present on the
Network Settings tab for the DNS Name Lookup feature to function.
DUA1611-0AAA02.book Page 64 Thursday, August 2, 2001 4:01 PM