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Configuring the Switch
IP Configuration
Configuring the Switch
DHCP Operation
A significant difference between a DHCP configuration and a Bootp configu-
ration is that an IP address assignment from a DHCP server is automatic,
requiring no configuration of the DHCP server. Using that automatic feature,
though, the address is temporarily leased. Periodically the switch is required
to renew its lease of the IP configuration.
As a result, the IP addressing provided by the server may be different each
time the switch reboots or renews its configuration from the server. This may
cause a problem for you if you access the switch through the web browser
interface, since the IP address is used as the browser URL.
However, you can fix the address assignment for the switch by doing either
of the following:
■ Using the switch’s MAC address as an identifier, configure the server with
a “Reservation” so that it will always assign the same IP address to the
switch. (For MAC address information, refer to appendix B, “MAC
Address Management”.)
■ Configure the server to issue an “infinite” lease.
For more information on either of these procedures, refer to the documenta-
tion provided with the DHCP server.
Bootp Operation
When a Bootp server receives a request it searches its Bootp database for a
record entry that matches the MAC address in the Bootp request from the
switch. If a match is found, the configuration data in the associated database
record is returned to the switch. For most Unix systems, the Bootp database
is contained in the /etc/bootptab file. In contrast to DHCP operation, Bootp
configurations are always the same for each receiving device. That is, the
Bootp server replies to a request with a configuration previously stored in the
server and designated for the requesting device.
Bootp Database Record Entries. A minimal entry in the Bootp table file
/etc/bootptab to provide an IP address and subnet mask to the switch would
be similar to this entry:
j3299switch:\
ht=ether:\
ha=0060b0123456:\
ip=11.22.33.44:\
sm=255.255.248.0:\
vm=rfc1048
Sraswb.book : SIER_SW6.FM Page 11 Tuesday, June 30, 1998 12:20 PM