The DHCP Snooping function supports Option82. Option82 can contain 255 sub options at most. Maipu device supports two sub options, that is, Circuit ID and Remote ID.
Configuration Condition
Before configuring DHCP Snooping Option82, first complete the following task:
- Enable the DHCP Snooping function
Configure the Processing Policy of Option82
After the port is configured with the disable information, whatever option packet the port receives, it is forwarded as it is.
Table 6-5 Configure the processing policy of Option82
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Enable the Option82 of the DHCP Snooping function
|
dhcp-snooping information enable
|
Mandatory
By default, the Option82 of the DHCP Snooping function is disabled.
|
Enter the L2 Ethernet interface configuration mode
|
interface interface-name
|
Either
After entering the L2 Ethernet interface configuration mode, the subsequent configuration just takes effect on the current port. After entering the aggregation group configuration mode, the subsequent configuration just takes effect on the aggregation group.
|
Enter the aggregation group configuration mode
|
interface link-aggregation link-aggregation-id
|
Configure the processing policy of Option82
|
dhcp-snooping information disable
|
Optional
By default, the processing policy for the DHCP request packet with Option82 is replace, that is, forward after replacing.
|
Configure Remote ID
The content of Remote ID includes default content and non-default content. The filling format of the default content of Remote ID is as follows:
![The filling format of the default content of Remote ID](/storage/images/Document/Maipu/security/7-2.jpg)
Figure 7-2 The filling format of the default content of Remote ID
The non-default content includes customized character string and device name, and needs to be configured to take effect in the user configuration format. The filling format of the non-default content of Remote ID is as follows:
![The filling format of the non-default content of Remote ID](/storage/images/Document/Maipu/security/7-3.jpg)
Figure 7-3 The filling format of the non-default content of Remote ID
Table 7-5 Configure the content of Remote ID
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Configure the content of Remote ID
|
dhcp-snooping information format remote-id { string | default | hostname }
|
Mandatory
By default, the content of Remote ID is the default content, that is, the MAC address of the device port.
|
Configure Circuit ID
The content of Circuit ID includes default content and non-default content. The filling format of the default content of Circuit ID is as follows:
![The filling format of the default content of Circuit ID](/storage/images/Document/Maipu/security/7-4.jpg)
Figure 7-4 The filling format of the default content of Circuit ID
The non-default content needs to be configured to take effect in the user configuration format. The filling format of the non-default content of Circuit ID is as follows:
![The filling format of the non-default content of Circuit ID](/storage/images/Document/Maipu/security/7-5.jpg)
Figure 7-5 The filling format of the non-default content of Circuit ID
Table 7-6 Configure the content of Circuit ID
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Enter the L2 Ethernet interface configuration mode
|
interface interface-name
|
Either
After entering the L2 Ethernet interface
configuration mode, the subsequent configuration just takes effect on the current port. After entering the aggregation group configuration mode, the subsequent configuration just takes effect on the aggregation group.
|
Enter the aggregation group configuration mode
|
interface link-aggregation link-aggregation-id
|
Configure the content of Circuit ID
|
dhcp-snooping information format circuit-id { string | default }
|
Mandatory
By default, the content of Circuit ID is the default content.
|
Configure Filling Format of Option82
The filling format of Option82 includes default format and user configuration format.
When the filling format is the default format, the contents of Remote ID and Circuit ID are both default content; only after the filling format is configured as the user configuration format, the non-default contents of Remote ID and Circuit ID can take effect.
Table 7-7 Configure the filling format of Option82
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Configure the filling format of Option82
|
dhcp-snooping information format { default | user-config }
|
Mandatory
By default, the filling format is the default format.
|
Configure Packet Processing Policy of Option82
Configure the packet processing policy of Option82. We can adopt different forwarding policies for the DHCP request packet containing Option82.
Table 7-8 Configure the packet processing policy of Option82
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Configure the packet processing policy of Option82
|
dhcp-snooping information policy { drop | keep | replace }
|
Mandatory
By default, the processing policy is replace.
|