Table 369: Components of the Port Security Topology
Settings
Properties
One EX3200-24P, 24 ports (8 PoE ports)
Switch hardware
employee-vlan
, tag
20
VLAN name and ID
192.0.2.16/28
192.0.2.17
through
192.0.2.30
192.0.2.31
is subnet's broadcast address
VLAN subnets
ge-0/0/1
,
ge-0/0/2
,
ge-0/0/3
,
ge-0/0/8
Interfaces in
employee-vlan
ge-0/0/8
Interface for DHCP server
In this example, the switch has already been configured as follows:
•
Secure port access is activated on the switch.
•
DHCP snooping is disabled on the VLAN
employee-vlan
.
•
All access ports are untrusted, which is the default setting.
Configuration
To configure DHCP snooping and dynamic ARP inspection (DAI) to protect the switch
against ARP attacks:
CLI Quick
Configuration
To quickly configure DHCP snooping and dynamic ARP inspection (DAI), copy the following
commands and paste them into the switch terminal window:
[edit ethernet-switching-options secure-access-port]
set interface ge-0/0/8
dhcp-trusted
set vlan employee-vlan
examine-dhcp
set vlan employee-vlan
arp-inspection
Step-by-Step
Procedure
Configure DHCP snooping and dynamic ARP inspection (DAI) on the VLAN:
Set the
ge-0/0/8
interface as trusted:
1.
[edit ethernet-switching-options secure-access-port]
user@switch#
set interface ge-0/0/8 dhcp-trusted
2.
Enable DHCP snooping on the VLAN:
[edit ethernet-switching-options secure-access-port]
user@switch#
set vlan employee-vlan examine-dhcp
3.
Enable DAI on the VLAN:
[edit ethernet-switching-options secure-access-port]
user@switch#
set vlan employee-vlan arp-inspection
Results
Check the results of the configuration:
[edit ethernet-switching-options secure-access-port]
user@switch# show
Copyright © 2010, Juniper Networks, Inc.
2868
Complete Software Guide for Junos
®
OS for EX Series Ethernet Switches, Release 10.3
Summary of Contents for JUNOS OS 10.3 - SOFTWARE
Page 325: ...CHAPTER 17 Operational Mode Commands for System Setup 229 Copyright 2010 Juniper Networks Inc ...
Page 1323: ...CHAPTER 56 Operational Mode Commands for Interfaces 1227 Copyright 2010 Juniper Networks Inc ...
Page 2841: ...CHAPTER 86 Operational Commands for 802 1X 2745 Copyright 2010 Juniper Networks Inc ...
Page 3367: ...CHAPTER 113 Operational Mode Commands for CoS 3271 Copyright 2010 Juniper Networks Inc ...
Page 3435: ...CHAPTER 120 Operational Mode Commands for PoE 3339 Copyright 2010 Juniper Networks Inc ...
Page 3529: ...CHAPTER 126 Operational Mode Commands for MPLS 3433 Copyright 2010 Juniper Networks Inc ...