Administrator Guide

Configuring dynamic ARP inspection-limit
To configure dynamic ARP inspection rate limit on a port, perform the following task.
1. Enter into global configuration mode.
EXEC Privilege mode
configure terminal
2. Select the interface to be configured.
CONFIGURATION mode
interface interface-name
3. Configure ARP packet inspection rate limiting.
INTERFACE CONFIGURATION mode
arp inspection-limit {rate pps [interval seconds]}
The rate packet per second (pps) range is from 1 to 2048. The default is 15.
The rate burst interval range is from 1 to 15 seconds. The default is 1.
DellEMC# show running-config interface gigabitethernet 1/1
interface GigabitEthernet 1/1
no ip address
switchport
arp inspection-limit rate 15 interval 1
no shutdown
DellEMC#
Bypassing the ARP Inspection
You can configure a port to skip ARP inspection by defining the interface as trusted, which is useful in multi-switch environments.
ARPs received on trusted ports bypass validation against the binding table. All ports are untrusted by default.
To bypass the ARP inspection, use the following command.
• Specify an interface as trusted so that ARPs are not validated against the binding table.
INTERFACE mode
arp inspection-trust
Dynamic ARP inspection is supported on Layer 2 and Layer 3.
Source Address Validation
Using the DHCP binding table, Dell EMC Networking OS can perform three types of source address validation (SAV).
Table 18. Three Types of Source Address Validation
Source Address Validation Description
IP Source Address Validation Prevents IP spoofing by forwarding only IP packets that have been
validated against the DHCP binding table.
DHCP MAC Source Address Validation Verifies a DHCP packet’s source hardware address matches the
client hardware address field (CHADDR) in the payload.
IP+MAC Source Address Validation Verifies that the IP source address and MAC source address are a
legitimate pair.
Enabling IP Source Address Validation
IP source address validation (SAV) prevents IP spoofing by forwarding only IP packets that have been validated against the DHCP binding
table.
A spoofed IP packet is one in which the IP source address is strategically chosen to disguise the attacker. For example, using ARP
spoofing, an attacker can assume a legitimate client’s identity and receive traffic addressed to it. Then the attacker can spoof the client’s
IP address to interact with other clients.
Dynamic Host Configuration Protocol (DHCP)
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