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20-5
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
78-11380-10
Chapter 20 Configuring DHCP Features
Configuring DHCP Features
Figure 20-2 Suboption Packet Formats
Configuring DHCP Features
These sections describe how to configure DHCP snooping and option 82 on your switch:
•
Default DHCP Configuration, page 20-5
•
DHCP Snooping Configuration Guidelines, page 20-6
•
Configuring the DHCP Server, page 20-6
•
Enabling DHCP Snooping and Option 82, page 20-7
Default DHCP Configuration
Table 20-1
shows the default DHCP configuration.
Length
Length
Circuit
ID type
Suboption
type
Circuit ID Suboption Frame Format
Remote ID Suboption Frame Format
6 bytes
MAC address
1 byte 1 byte 1 byte
Suboption
type
1 byte
Length
Length
Remote
ID type
1 byte 1 byte 1 byte
1 byte
116300
4
0
6
1
6
0
8
2
Module Port
1 byte 1 byte
2 bytes
VLAN
Table 20-1 Default DHCP Configuration
Feature
Default Setting
DHCP server
Enabled
1
DHCP relay agent
Enabled
2
DHCP packet forwarding address
None configured
Checking the relay agent information
Enabled (invalid messages are dropped)
2
DHCP relay agent forwarding policy
Replace the existing relay agent information
2
DHCP snooping enabled globally
Disabled
DHCP snooping information option
Enabled
DHCP snooping limit rate
None configured