3com 3CR17451-91 Manuel D’Utilisation

Page de 86
Setting Up Overview
31
CAUTION: To protect your Switch from unauthorized access, you must 
change all three default passwords as soon as possible, even if you do not 
intend to actively manage your Switch. For more information on default 
users and changing default passwords, see 
“Default Users and 
Passwords” on page 43
.
IP Configuration
You can use one of the following methods to allocate IP information to 
your Switch (essential if you wish to manage your Switch across the 
network).
Manual IP Configuration 
You can choose to configure the IP information yourself. The Switch 
remembers the information that you enter until you change it again or 
set the configuration method to Automatic.
You should use the Manual IP configuration method if:
you do not have a DHCP server on your network, or
you want to remove the risk of the IP address ever changing, or
your DHCP server does not allow you to allocate static IP addresses. 
(Static IP addresses are necessary to ensure that the Switch is always 
allocated the same IP information.)
For most installations, 3Com recommends that you configure the Switch 
IP information manually. This makes management simpler and more 
reliable as it is not dependent on a DHCP server, and eliminates the risk of 
the IP address changing.
If you wish to manually enter IP information for your Switch, work 
through the “Manually Configuring IP Information” section on page 33.
Automatic IP Configuration
By default the Switch tries to configure itself with IP information without 
requesting user intervention. It tries to obtain an IP address from a DHCP 
server on the network.
It takes up to 5 minutes for your Switch to obtain an IP address after it 
has been powered up.
When using automatic IP configuration it is important that the IP address 
of the Switch is static, otherwise you will not know what the IP address is 
and it will be difficult to manage. Most DHCP servers allow static IP 
DUA1745-0AAA03.book  Page 31  Friday, April 8, 2005  12:34 PM