No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

CLI-based Configuration Guide - Security

AR500, AR510, and AR530 V200R007

This document describes the configurations of Security, including AAA, DAA,NAC, BRAS Access, ACL, Firewall, Deep Security Defense, Local Attack Defense;Attack Defense, Traffic Suppression, ARP Security, Port Security, DHCP Snooping, IPSG, URPF, PKI, SSL, HTTPS, Keychain, separating the management plane from the service plane, security risks.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Inserting the Option 82 Field in a DHCP Message

Inserting the Option 82 Field in a DHCP Message

You can configure a device to insert the Option 82 field in a DHCP message to notify the DHCP server of the DHCP client location.

Context

The Option 82 field records the location of a DHCP client. A device inserts the Option 82 field into a DHCP Request message to notify the DHCP server of the DHCP client location. The DHCP server can assign an IP address and other configurations to the DHCP client, ensuring DHCP client security.

NOTE:

DHCP Option 82 must be configured on the user-side of a device; otherwise, the DHCP message sent to the DHCP server will not carry Option 82.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. You can configure the device to insert the Option 82 field in a DHCP message in the interface view or VLAN view. If the configuration is performed in the VLAN view, the configuration takes effect for all DHCP messages from this VLAN that are received by the interface. If the configuration is performed in the interface view, the configuration takes effect only for the specified interface.

    View Steps
    VLAN view
    1. Run the vlan vlan-id command to enter the VLAN view.
    2. Run the dhcp option82 { insert | rebuild } enable command to enable the device to insert the Option 82 field in a DHCP message.

      By default, the device is disabled from inserting the Option 82 field in a DHCP message.

    3. Run the quit command to return to the system view.
    Interface view
    1. Run the interface interface-type interface-number command to enter the interface view.

    2. Run the dhcp option82 { insert | rebuild } enable command to enable the device to insert the Option 82 field in a DHCP message.

      By default, the device is disabled from inserting the Option 82 field in a DHCP message.

    3. Run the quit command to return to the system view.

  3. (Optional) You can configure the format of the Option 82 field in the system or interface view. If the configuration is performed in the system view, the configuration takes effect for all interfaces on the device. If the configuration is performed in the interface view, the configuration takes effect only for the specified interface.

    • All Option82 fields configured in the system view or in the same interface view share a length of 1-255 bytes. If their total length exceeds 255 bytes, some Option82 information will be lost.

    • There is no limit on the number of Option 82 fields configured on the device. However, a large number of Option 82 fields will occupy a lot of memory and prolong the device processing time. To ensure device performance, you are advised to configure Option 82 fields based on the service requirements and device memory size.

    View Steps
    System view
    1. Run the dhcp option82 [ vlan vlan-id ] [ ce-vlan ce-vlan-id ] [ circuit-id | remote-id ] format { default | common | extend | user-defined text } command to configure the format of the Option 82 field in a DHCP message.

      By default, the format of the Option 82 field in a DHCP message is default.

    Interface view
    1. Run the interface interface-type interface-number command to enter the interface view.

    2. Run the dhcp option82 [ vlan vlan-id ] [ ce-vlan ce-vlan-id ] [ circuit-id | remote-id ] format { default | common | extend | user-defined text } command to configure the format of the Option 82 field in a DHCP message.

      By default, the format of the Option 82 field in a DHCP message is default.

    3. Run the quit command to return to the system view.

  4. (Optional) Disable the interface from generating DHCP snooping binding entries after the DHCP snooping function has been enabled.

    When this configuration is performed in the VLAN view, the configuration takes effect for all DHCP users belonging to this VLAN on all interfaces. When this configuration is performed in the interface view, the configuration takes effect for all DHCP users connecting to this interface.

    By default, an interface generates DHCP snooping binding entries after DHCP snooping is enabled.

    Configuration Dimension

    Step

    VLAN-based configuration
    • For a batch of VLANs in the system view

      • Run the dhcp snooping enable no-user-binding vlan { vlan-id1 [ to vlan-id2 ] }&<1-10> command to disable the interfaces from generating DHCP snooping binding entries after DHCP snooping is enabled.

    • For a single VLAN in the VLAN view

      1. Run the vlan vlan-id command to enter the VLAN view.
      2. Run the dhcp snooping enable no-user-binding command to disable the interfaces from generating DHCP snooping binding entries after DHCP snooping is enabled.
      3. Run the quit command to return to the system view.
    Interface-based configuration
    1. Run the interface interface-type interface-number command to enter the interface view.
    2. Run the dhcp snooping enable no-user-binding command to disable the interfaces from generating DHCP snooping binding entries after DHCP snooping is enabled.
    3. Run the quit command to return to the system view.

Checking the Configuration

  • Run the display dhcp option82 configuration [ vlan vlan-id | interface interface-type interface-number ] command to view the DHCP Option 82 configuration.
Translation
Download
Updated: 2019-05-25

Document ID: EDOC1000097287

Views: 13778

Downloads: 40

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next