Users Guide

ManualsBrandsDell ManualsAccess PlatformsNetworking S3100 Series

1221

Secure DHCP Commands

DHCP as defined by RFC 2131 provides no authentication or security mechanisms. Secure DHCP is a suite of features that protects

networks that use dynamic address allocation from spoofing and attacks.

clear ip dhcp snooping

Clear the DHCP binding table.

Syntax

clear ip dhcp snooping binding

Defaults none

Command Modes EXEC Privilege

Command History

This guide is platform-specific. For command information about other platforms, see the relevant Dell Networking

OS Command Line Reference Guide.

Version Description

9.8(2.0) Introduced on the S3100 series.

9.8(1.0) Introduced on the Z9100-ON.

9.8(0.0P5) Introduced on the S4048-ON.

9.8(0.0P2) Introduced on the S3048-ON.

9.7(0.0) Introduced on the S6000–ON.

9.2(1.0) Introduced on the Z9500.

9.0.2.0 Introduced on the S6000.

8.3.19.0 Introduced on the S4820T.

8.3.11.1 Introduced on the Z9000.

8.3.7.0 Introduced on the S4810.

7.8.1.0 Introduced on the C-Series and S-Series.

Commands

• show ip dhcp snooping — display the contents of the DHCP binding table.

ip dhcp relay

Enable Option 82.

Syntax

ip dhcp relay information-option [trust-downstream | vrf]

Parameters

trust-downstream Configure the system to trust Option 82 when it is received from the previous-hop router.

vrf Enter the keyword vrf to include VRF related information in the Option 82. This

configuration enables the relay agent to include VRF related information when it forwards

the broadcasts from client to DHCP server.

Defaults Disabled.

Command Modes CONFIGURATION