Contents

Introduction· 1

Prerequisites· 1

Example: Configuring traffic filtering· 1

Network configuration· 1

Analysis· 2

Applicable hardware and software versions· 3

Restrictions and guidelines· 4

Procedures· 4

Configuring Device A· 4

Configuring Device B· 5

Verifying the configuration· 5

Configuration files· 6

 

Introduction

This document provides traffic filtering configuration examples.

Prerequisites

The configuration examples in this document were created and verified in a lab environment, and all the devices were started with the factory default configuration. When you are working on a live network, make sure you understand the potential impact of every command on your network.

This document assumes that you have basic knowledge of traffic filtering.

Example: Configuring traffic filtering

Network configuration

As shown in Figure 1, a company has three branches, each of which has a Marketing department and a Finance department. All Marketing departments belong to VLAN 20. All Finance departments belong to VLAN 30.

Configure traffic filtering to meet the following requirements:

·     HTTP traffic from the Marketing department in each branch is denied.

·     In Branch B, only Host A and Host B can access the server.

·     The Marketing departments in three branches can access one another, and the Finance departments in three branches can access one another.

Figure 1 Network diagram

 

Analysis

To meet the network requirements, you must perform the following tasks:

·     To deny HTTP traffic from the Marketing departments, use one of the following methods:

¡     Filter outgoing traffic from the subnet 192.168.4.0/24 on the interfaces that connect Device B, Device C, and Device D to Device A.

This method has poor scalability, because new branches require the same configuration on their access switches.

¡     Filter outgoing traffic from the subnet 192.168.4.0/24 on interface GigabitEthernet 1/0/4 of Device A.

This method wastes processing capabilities of Device A, because Device A must internally forward all incoming traffic to interface GigabitEthernet 1/0/4.

¡     Configure a QoS policy to deny HTTP traffic from the Marketing departments.

This method can automatically adapt to changing network topologies and also saves hardware resources by denying traffic on the incoming interface. This example uses this method.

·     To allow only Host A and Host B to access the server in Branch B, perform the following tasks:

¡     Configure an ACL on GigabitEthernet 1/0/1 to allow packets from 192.168.4.10/24 and 192.168.4.15/24.

¡     Set the default packet filtering action to deny to deny packets that do not match the configured ACL.

·     To allow traffic from Marketing departments and Finance departments (except HTTP traffic) to the Internet and to allow access among Marketing departments and among Finance departments, perform the following tasks:

¡     Configure GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 as trunk ports.

¡     Assign these interfaces to VLAN 20 and VLAN 30.

Applicable hardware and software versions

The following matrix shows the hardware and software versions to which this configuration example is applicable:

 

Hardware	Software version
S6520XE-HI switch series	Supported in Release 11xx
S5560X-EI switch series	Supported in Release 111x
S5500V2-EI switch series	Supported in Release 111x
MS4520V2-30F switch	Supported in Release 111x
S5560S-EI switch series S5560S-SI switch series	Supported in Release 612x
S5130S-HI switch series S5130S-EI switch series S5130S-SI switch series S5130S-LI switch series	Supported in Release 612x
S5120V2-SI switch series S5120V2-LI switch series	Supported in Release 612x
S3100V3-EI switch series S3100V3-SI switch series	Supported in Release 612x
S5110V2 switch series	Supported in Release 612x
S5110V2-SI switch series	Supported in Release 612x
S5000V3-EI switch series	Supported in Release 612x
S5000E-X switch series	Supported in Release 612x
WAS6000 switch series	Supported in Release 612x
E128C switch E152C switch E500C switch series E500D switch series	Supported in Release 612x
MS4520V2 switch series (except the MS4520V2-30F switch)	Supported in Release 612x
MS4320V2 switch series MS4300V2 switch series MS4320 switch series MS4200 switch series	Supported in Release 612x
WS5850-WiNet switch series	Supported in Release 612x
WS5820-WiNet switch series WS5810-WiNet switch series	Supported in Release 612x

 

Restrictions and guidelines

If a traffic behavior is configured with the filter deny action, all other actions in the behavior except traffic accounting do not take effect.

Procedures

Configuring Device A

# Create VLAN 20 and VLAN 30.

<DeviceA> system-view

[DeviceA] vlan 20

[DeviceA-vlan20]quit

[DeviceA] vlan 30

[DeviceA-vlan30]quit

# Add GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 to interface range named myport.

[DeviceA] interface range name myport interface GigabitEthernet 1/0/1 to GigabitEthernet 1/0/4

# Configures interfaces GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 as trunk ports, assign them to VLAN 20 and VLAN 30, and remove them from VLAN 1.

[DeviceA-if-range-myport] port link-type trunk

[DeviceA-if-range-myport] port trunk permit vlan 20 30

[DeviceA-if-range-myport] undo port trunk permit vlan 1

[DeviceA-if-range-myport] quit

# Configure advanced IPv4 ACL 3000 to match HTTP traffic from subnet 192.168.4.0/24.

[DeviceA] acl advanced 3000

[DeviceA-acl-ipv4-adv-3000] rule deny tcp source 192.168.4.0 0.0.0.255 source-port eq 80

[DeviceA-acl-ipv4-adv-3000] quit

# Create a class named vlan20_http, and use ACL 3000 as the match criterion.

[DeviceA] traffic classifier vlan20_http

[DeviceA-classifier-vlan20_http] if-match acl 3000

[DeviceA-classifier-vlan20_http] quit

# Create a behavior named vlan20_http, and configure traffic filtering to deny traffic of the class vlan20_http.

[DeviceA] traffic behavior vlan20_http

[DeviceA-behavior-vlan20_http] filter deny

[DeviceA-behavior-vlan20_http] quit

# Create a QoS policy named vlan20_http, and associate the class vlan20_http with the behavior vlan20_http in the QoS policy.

[DeviceA] qos policy vlan20_http

[DeviceA-qospolicy-vlan20_http] classifier vlan20_http behavior vlan20_http

[DeviceA-qospolicy-vlan20_http] quit

# Apply the QoS policy vlan20_http to the inbound direction of VLAN 20 and VLAN 30.

[DeviceA] qos vlan-policy vlan20_http vlan 20 30 inbound

Configuring Device B

# Configure basic IPv4 ACL 2000 to permit traffic from Host A and Host B.

[DeviceB] acl basic 2000

[DeviceB-acl-ipv4-basic-2000] rule permit source 192.168.4.10 0

[DeviceB-acl-ipv4-basic-2000] rule permit source 192.168.4.15 0

[DeviceB-acl-ipv4-basic-2000] quit

# Set the packet filtering default action to deny.

[DeviceB] packet-filter default deny

# Apply ACL 2000 to interface GigabitEthernet 1/0/1 to filter outgoing traffic.

[DeviceB] interface GigabitEthernet 1/0/1

[DeviceB-GigabitEthernet1/0/1] packet-filter 2000 outbound

Verifying the configuration

# Verify the QoS policy applied to the inbound direction of VLAN 20 and VLAN 30.

[DeviceA]display qos vlan-policy vlan inbound

  Direction: Inbound

  Policy: vlan20_http

   Classifier: vlan20_http

     Operator: AND

     Rule(s) :

      If-match acl 3000

     Behavior: vlan20_http

      Filter enable: Deny

Vlan 30

  Direction: Inbound

  Policy: vlan20_http

   Classifier: vlan20_http

     Operator: AND

     Rule(s) :

      If-match acl 3000

     Behavior: vlan20_http

      Filter enable: Deny

# Display application details of ACLs for incoming packet filtering on GigabitEthernet 1/0/1.

[DeviceB] display packet-filter verbose interface GigabitEthernet 1/0/1 outbound

Interface: GigabitEthernet1/0/1

 Outbound policy:

  IPv4 ACL 2000

   rule 0 permit source 192.168.4.10 0

  IPv4 default action: Deny

Configuration files

	IMPORTANT: The port link-mode bridge command is available only on the following switches: ·     S6520XE-HI switch series. ·     S5560X-EI switch series. ·     S5500V2-EI switch series. ·     MS4520V2-30F switch.

 

·     Device A:

#                                                                              

vlan 20                                                                        

#                                                                              

vlan 30

#                                                                             

interface range name myport interface GigabitEthernet1/0/1 to GigabitEthernet1/0/4

#                                                                              

acl advanced 3000                                                                

 rule 0 deny tcp source 192.168.4.0 0.0.0.255 source-port eq www               

#                                                                              

traffic classifier vlan20_http operator and                                    

 if-match acl 3000                                                             

#                                                                              

traffic behavior vlan20_http                                                   

 filter deny                                                                   

#                                                                              

qos policy vlan20_http                                                         

 classifier vlan20_http behavior vlan20_http

#                                                                              

 qos vlan-policy vlan20_http vlan 20 inbound                                    

 qos vlan-policy vlan20_http vlan 30 inbound                                   

#

interface GigabitEthernet1/0/1                                            

 port link-mode bridge                                                          

 port link-type trunk                                                          

 undo port trunk permit vlan 1                                                 

 port trunk permit vlan 20 30                                                  

#                                                                               

interface GigabitEthernet1/0/2                                            

 port link-mode bridge                                                         

 port link-type trunk                                                           

 undo port trunk permit vlan 1                                                 

 port trunk permit vlan 20 30                                                  

#                                                                               

interface GigabitEthernet1/0/3                                            

 port link-mode bridge                                                         

 port link-type trunk                                                           

 undo port trunk permit vlan 1                                                 

 port trunk permit vlan 20 30                                                  

#                                                                               

interface GigabitEthernet1/0/4                                            

 port link-mode bridge                                                         

 port link-type trunk                                                          

 undo port trunk permit vlan 1                                                 

 port trunk permit vlan 20 30

·     Device B:

#                                                                              

acl basic 2000                                                                 

 rule 0 permit source 192.168.4.10 0

#                                                                              

 packet-filter default deny 

#                                                                              

interface GigabitEthernet1/0/1                   

 port link-mode bridge                                                         

 packet-filter 2000 outbound                                                   

#