20-9
Catalyst 2975 Switch Software Configuration Guide
OL-19720-02
Chapter 20 Configuring DHCP Features and IP Source Guard Features
Configuring DHCP Snooping
Configuring DHCP Snooping
These sections contain this configuration information:
•
Default DHCP Snooping Configuration, page 20-9
•
DHCP Snooping Configuration Guidelines, page 20-9
•
Configuring the DHCP Relay Agent, page 20-11
•
Enabling DHCP Snooping and Option 82, page 20-11
•
Enabling the DHCP Snooping Binding Database Agent, page 20-13
Default DHCP Snooping Configuration
shows the default DHCP snooping configuration.
DHCP Snooping Configuration Guidelines
These are the configuration guidelines for DHCP snooping.
•
You must globally enable DHCP snooping on the switch.
•
DHCP snooping is not active until DHCP snooping is enabled on a VLAN.
Table 20-1
Default DHCP Snooping Configuration
Feature
Default Setting
DHCP server
Enabled in Cisco IOS software, requires configuration
1
1.
The switch responds to DHCP requests only if it is configured as a DHCP server.
DHCP relay agent
Enabled
2
2.
The switch relays DHCP packets only if the IP address of the DHCP server is configured on the SVI of the DHCP client.
DHCP packet forwarding address
None configured
Checking the relay agent information
Enabled (invalid messages are dropped)
DHCP relay agent forwarding policy
Replace the existing relay agent information
DHCP snooping enabled globally
Disabled
DHCP snooping information option
Enabled
DHCP snooping option to accept packets on
untrusted input interfaces
3
3.
Use this feature when the switch is an aggregation switch that receives packets with option-82 information from an edge switch.
Disabled
DHCP snooping limit rate
None configured
DHCP snooping trust
Untrusted
DHCP snooping VLAN
Disabled
DHCP snooping MAC address verification
Enabled
DHCP snooping binding database agent
Enabled in Cisco IOS software, requires configuration. This feature is
operational only when a destination is configured.
Содержание 2975 - Catalyst LAN Base Switch
Страница 36: ...Contents xxxvi Catalyst 2975 Switch Software Configuration Guide OL 19720 02 ...
Страница 40: ...xxxviii Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Preface ...
Страница 62: ...1 22 Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Chapter 1 Overview Where to Go Next ...
Страница 398: ...13 30 Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Chapter 13 Configuring VLANs Configuring VMPS ...
Страница 424: ...15 18 Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Chapter 15 Configuring VTP Monitoring VTP ...
Страница 628: ...26 8 Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Chapter 26 Configuring UDLD Displaying UDLD Status ...
Страница 660: ...28 8 Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Chapter 28 Configuring RMON Displaying RMON Status ...
Страница 888: ...38 32 Catalyst 2975 Switch Software Configuration Guide OL 19720 02 Chapter 38 Troubleshooting Troubleshooting Tables ...