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Extend your networking skill set by

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Self-paced exercise guide

Module 1 - Exercise 1: Initial Configuration

Table of Contents

Table of Contents .............................................................................................................................................. 2

Overview............................................................................................................................................................. 3

Exercise 1: Initial Configuration ..................................................................................................................... 5

Exercise 2: Load Balancing ............................................................................................................................ 15

Exercise 3: Content Switching ....................................................................................................................... 21

Exercise 4: SSL Offload ................................................................................................................................. 32

Exercise 5: HTTP header modification ....................................................................................................... 40

Exercise 6: HTTP to HTTPs redirection and URL body rewrite ............................................................ 52


Overview

Hands-on Training Module

This training module has the following details:

Objective This lab provides hands on training on the core NetScaler functionality

Audience Primary: Partners and customers

Lab Environment Details

Machine Details

AD.training.lab Domain controller, DHCP, DNS

NS10_HA1 Virtual instance of a NetScaler appliance (HA node)

NS10_HA2 Virtual instance of a NetScaler appliance (HA node)

Win7Client Administrative workstation

Apache_MySQL_1 Linux server with Apache, PHP, MySQL



SQLServer Microsoft SQL 2008 server and Microsoft Certificate Services

WebBlue IIS server, PHP, WebGoat

WebGreen IIS server, PHP, WebGoat

WebRed IIS server, PHP, WebGoat


Lab Topology Diagram

Remote Network

Internal Router

Public Network

EXT-Win_7

Internal network

INT-Win_7 NS10_node1

NS10_node3

NS10_node2

192.168.10.X/24

AD/DNS/CA

172.16.1.0/24

Apache_2

Apache_3

Apache_1

172.16.2.0/24

NS10_HA1

NS10_HA2

WebGreen

WebRed

WebBlueSQLServer

SQLServer2

XD

XA1

XA1

VDA

NOTE: If prompted with a dialog to restart on any virtual machine, always select Restart Later.

Required Lab Credentials

Below are the login credentials required to connect to the workshop system and complete the lab

exercises.

Machine IP Address Username Password

AD.training.lab 192.168.10.11 TRAINING\Administrator Citrix123

NS10_HA1 NSIP: 192.168.10.220 SNIP: 192.168.10.90

nsroot nsroot

NS10_HA2 NSIP: 192.168.10.225 SNIP: 192.168.10.90

nsroot nsroot

Win7Client DHCP assigned TRAINING\Administrator Citrix123

Apache_MySQL_1 192.168.10.13 root Citrix123



SQLServer 192.168.10.12 TRAINING\Administrator Citrix123

WebBlue 192.168.10.205 TRAINING\Administrator Citrix123

WebGreen 192.168.10.210 TRAINING\Administrator Citrix123

WebRed 192.168.10.215 TRAINING\Administrator Citrix123


Exercise 1: Initial Configuration

Overview

In this exercise you will configure the NetScaler with a management IP address, subnet IP and a DNS

name server. Additionally you will configure licensing and set up a high availability pair.

Step-by-step guidance

The lab environment required for this exercise is as follows:

1. NetScaler VPX appliance: (NS10_HA1)


3. Windows 7 Workstation: (Win7Client)

Estimated time to complete this lab: 20 minutes.

Step Action

1. In XenCenter, go to the networking tab of each NetScaler and confirm that the MAC

address is correct since it determines licensing.

NS10_HA1: 06:e0:89:e0:b0:fd

NS10_HA2: 22:64:cc:9b:ea:aa


Step Action

2. Go to the console tab of NS10_HA1 and NS10_HA2 virtual machines and set the

following Initial Network Address Configuration:

NS10_HA1:

IP Address: 192.168.10.220

Netmask: 255.255.255.0

Gateway: 192.168.10.1

Select option #4 to Save and quit.

NS10_HA2

IP Adress: 192.168.10.225

Netmask: 255.255.255.0

Gateway: 192.168.10.1

Select option #4 to Save and quit.

3. After the NetScaler VMs reboot, select the Win7Client VM and click the Console tab.


Step Action

4. Select the Send Ctrl+Alt+Del (Ctrl+Alt+Insert) button in the lower left hand corner of

XenCenter.

5. Login as…

Username: training\administrator

Password: Citrix123

6. Open Internet Explorer and navigate to http://192.168.10.220 .

7. The NetScaler Configuration Utility is displayed.

Login as…

Username: nsroot

Password: nsroot

8. On the bottom of the screen, select Setup Wizard…

9. Click Next on the Introduction screen.

http://192.168.10.220/


Step Action

10. On the Network Config screen, enter the following:

Host Name: NS10_HA1

Subnet IP (SNIP): 192.168.10.90

Netmask: 255.255.255.0

Click Next.

11. On the Choose Application screen, click Next.

12. Click Finish on the Summary screen. Then click Exit to close the setup wizard.

13. On the top right side of the screen, save your configuration by clicking on the Save button.

Click Yes to confirm.

14. Open another tab in Internet Explorer and repeat steps 6-13 for NS10_HA2

(192.168.10.225).

Host name: NS10_HA2

Subnet IP (SNIP): 192.168.10.90

Netmask: 255.255.255.0

15. On both nodes, use the CLI to copy the new license file to the /nsconfig/license

directory.

Select the NS10_HA1 virtual machine and click on the Console tab.

16. If the you do not see the login: prompt, hit the enter key once or twice.

Login as…

Username: nsroot

Password: nsroot


Step Action

17. At the NetScaler prompt, type shell.

18. You are now in the shell of NetScaler. Type the following command:

cp /var/license_backup/VPX_1000.lic /nsconfig/license/

Hit the Enter key.

19. Type exit to exit the shell.

20. Type reboot –warm to reboot the NetScaler.

Type Y and hit the Enter key to confirm you want to restart NetScaler.

The NetScaler now reboots.

21. Select the NS10_HA2 virtual machine in XenCenter and click on the Console tab.

22. Repeat steps 16-20 on NS10_HA2.

23. Select the Win7Client VM again. Close out your browser. Open a new instance of IE and

browse to http://192.168.10.220.

24. Login as…

Username: nsroot

Password: nsroot

25. Navigate to System>Licenses page and note all the licensed features.

http://192.168.10.220/


Step Action

26. Navigate to System > Settings > Configure basic features

Enable all features except HTTP Compression, Content Filter, Integrated Caching, and

Application Firewall.

Click OK.

27. Next we will configure a DNS Name Server on the NetScaler for name resolution.

NetScaler can be configured as a DNS Name server, but in this exercise we will point to an

external DNS server.

Navigate to DNS > Name Servers. Click Add.


Step Action

28. Enter IP address 192.168.10.11 (This is the lab Domain Controller) and click Create.

Click Close to close the Create Name Server window.

29. Minimize your IE window and double-click on the Putty application on your desktop.

30. Enter 192.168.10.220 in the Host Name field and click Open.


Step Action

31. Login as…

Username: nsroot

Password: nsroot

Click Yes on the security alert pop-up.

32. At the NetScaler prompt, run each of the following commands:

> show run

> sh ns ip (note the NSIP and SNIP)

> sh route

> sh ns feature

> sh ns mode

> sh ha node

> sh license

> show (tab complete to see all the available options)

> show ns (tab complete and check one or two options out)

33. Minimize the Putty window.


Step Action

34. Bring up the NetScaler Configuration Utility of NS10_HA1 again and navigate to System

> High Availability

Click Add.

35. Enter the IP of the NS10_HA2 (192.168.10.225).

Enable the Login credentials for remote system are different from self node

Username: nsroot

Password: nsroot

Click OK. Click Ok on the Information pop-up window.


Step Action

36. Click Refresh until Synchronization State is „SUCCESS‟ and save the configuration.

37. Bring up the Putty window again. Run the following command (hit enter a few times to get

the CLI moving)

> sh ha node | more

Note: Sync state Enabled. The Master State is (Primary) on NS10_HA1. If you run this

command on NS10_HA2, the Master State should show as (Secondary).

38. Failover is a feature that allows the secondary node to automatically receive incoming

requests in the event the primary node stops functioning.

Manually failover to the secondary node by entering the following commands:

> force ha failover

> sh ha node

Note: The Master State has changed. Force it back so NS10_HA1 is primary. Confirm that

the enabled features such as SSL Offload and Load Balancing are enabled.

39. Run the following command:

> sh ns feature | more

Confirm that SSL Offloading and Load Balancing are enabled.

40. Close out the putty window.

END OF EXERCISE

Exercise 2: Load Balancing

Overview

You want to demonstrate NetScaler load balancing. You need to configure the NetScaler to load balance

the Red, Blue and Green web servers. A server is a virtual representation of a physical server on the

backend. It consists of a server name and IP address. A service provides the connection between the

NetScaler appliance and the load balanced backend server. It consists of a server name, IP address, and

port, and data type to be served. If you prefer to identify servers by name rather than IP address, you can

create server objects and then specify a server's name instead of its IP address when you create a service.

After you create your services, you must create a virtual server to accept traffic for the load balanced Web

sites, applications, or servers. Once load balancing is configured, users connect to the load-balanced Web

site, application, or server through the virtual server‟s IP address or FQDN. Create servers, services and

virtual servers with persistence and protocol aware monitors.






4. IIS Web Server: (WebBlue)

5. IIS Web Server: (WebGreen)

6. IIS Web Server: (WebRed)


Step Action

1. In the NetScaler Configuration Utility of NS10_HA1, navigate to Load Balancing > Servers.

Click Add.

2. Enter the following configuration:

Server Name: Blue_Server

IP Address: 192.168.10.205

Click Create.

3. Repeat steps 2-3 to create the following servers:

Red_Server 192.168.10.215

Green_Server 192.168.10.210

After creating the servers, click Close.

4. Once done, you should see the servers created as follows.

5. Navigate to Load Balancing > Services. Click Add.

6. Create service objects for the servers created in the steps 1-4.

Enter the following configuration:

Service Name: Blue_Service

Server: Blue_Server (192.168.10.205)

Protocol: HTTP

Port: 80

Click Create.

7. Repeat steps 5-6 to create services for the following:

Red_Service 192.168.10.215

Green_Service 192.168.10.210

8. Once you are done, click Close. You should see the following services:

9. Navigate to Load Balancing > Virtual Server. Click Add.

10. Create a virtual server with the following configuration:

Name: RBG1

Protocol : HTTP

IP address: 192.168.10.216

Port: 80

Bind all three services by checking the box next to each service.

Click Create.

11. Open another browser tab and browse to http://192.168.10.216 . Refresh multiple times. The Red

Blue and Green web servers should be load balanced since no persistence is configured.

12. Go to Load Balancing > Services and disable two of the three services.

13. Test load balancing by browsing to http://192.168.10.216 again. You should connect to the same

server.

14. Re-Enable the services when done.

15. Go back to the NetScaler Configuration Utility and open the RBG1 virtual server.

Select the Method and Persistence tab.

16. Configure the following:

Method: change from Least Connection (Default) to Round Robin.

Persistence: CookieInsert

Time-Out value: Change from 2 (Default) to 0

http://192.168.10.216/

http://192.168.10.216/

17. A DNS record was created for 192.168.10.216. Browse to http://web1.training.lab and refresh

multiple times. This time you will notice that your session will persist to either the Red, Blue or

Green server for the duration of the session.

18. In the NetScaler Configuration Utility, navigate to Loadbalancing > Services.

Double-click the Blue_Service.

19. Select the http monitor from the list of available monitors on the left.

Click Add.

Select the tcp-default monitor from the list of configured monitors on the right.

Click Remove.

The HTTP monitor expects a 200 OK response code to consider the service state as UP.

Click OK.

Click OK on the warning as this only informs you that the default TCP monitor cannot be

unbound. Since we are selecting a new HTTP monitor, the health-check is still performed.

20. Click Close and Save the configuration.

END OF EXERCISE

http://web1.training.lab/

Exercise 3: Content Switching

Overview

You want to demonstrate NetScaler Content Switching. You need to configure NetScaler with a Content

Switching virtual server to achieve the following:

HTTP requests to home.php should be switched to a load balancing virtual server with

CookieInsert persistence and Round Robin load balancing.

HTTP requests for blue.php, red.php, and green.php should be switched to their own respective

servers.

HTTP requests that meet no configured content switching policy should trigger the Default

content switching policy and be switched to a load balancing virtual server with no persistence and

Round Robin load balancing.

In order to achieve this objective, the following must be configured

Server, services and load balancing virtual servers for each web server

The three services (Red, Blue, Green) are bound to non-directly addressable load balancing virtual

servers

Multiple content switching policies (e.g. HTTP.REQ.URL.CONTAINS("blue.php"))

A content switching virtual server with bound policies.










Step Action

1. In the NetScaler Configuration Utility, navigate to Load Balancing > Virtual Servers.

Delete the RBG1 virtual server.

2. Create a new virtual server with the following configuration:

Name: RBG_Default

Uncheck the Directly Addressable box.

Bind all services to this virtual server.

3. Select the Method and Persistence tab.

Configure the following:

Method: Round Robin

Persistence: None (No Persistence)

4. Create a new virtual server.


Name: RBG_Home


Bind all services to this virtual server.


Method: Round Robin


Time-out: 0



Name: RBG_Red


Bind only the Red service to this virtual server.



Method: Round Robin


Time-out: 0



Name: RBG_Blue


Bind only the Blue service to this virtual server.



Method: Round Robin


Time-out: 0



Name: RBG_Green


Bind only the Green service to this virtual server.



Method: Round Robin


Time-out: 0

12. You should have the following virtual servers configured:

13. Navigate to Content Switching > Policies.

Click Add.

14. Add a policy with the following configuration:

Name: Home_Policy

Click Configure.

15. In the Expression section type:

HTTP.REQ.URL.CONTAINS(“home.php”)

Click Create to close the Create Expression window.

16. Click Create to close the Create Content Switching Policy window.

17. Repeat steps 15-17 to create the following policies:

Name: Red_Policy

Expression: HTTP.REQ.URL.CONTAINS(“red.php”)

&

Name: Blue_Policy

Expression: HTTP.REQ.URL.CONTAINS(“blue.php”)

&

Name: Green_Policy

Expression: HTTP.REQ.URL.CONTAINS(“green.php”)

18. Navigate to Content Switching > Virtual Servers.

Click Add.


Name: RBG_CSW

IP Address: 192.168.10.217

Protocol: HTTP

Port: 80

Step Action

20. Note: The content switching virtual server‟s state

is UP although no policies have been bound.

Browse to https://192.168.10.217 . The service is

unavailable when browsing to the address.

21. Open the RBG_CSW virtual server. Click Insert Policy

22. Select the Home_Policy.

23. Click the dropdown arrow under the GoTo Expression column and select the blank option.

https://192.168.10.217/

24. Select the dropdown arrow under the Target column and select RBG_Home.

25. Double-click the text box under the Priority column and change the priority to 120.

Hit the Enter key.

26. Bind the remaining content switching policies to the respective targets (ie: Red_Policy to

RBG_Red etc…). Configure the priorities in those policies as indicated below.

27. A new DNS record was created for 192.168.10.217. Open another browser tab and browse to

http://web2.training.lab. Refresh multiple times. The Red Blue and Green web servers should be

load balanced in a round robin manner. This is because your request hit the Default policy and was

switched to RBG_Default which has no persistence is configured.

28. Change the request URL to http://web2.training.lab/home.php. Note: Hitting refresh multiple

http://web2.training.lab/

http://web2.training.lab/home.php

times will keep you on the same server since your request was sent to the RBG_Home virtual server

which has CookieInsert configured for persistence.

29. Change the request URL to http://web2.training.lab/red.php. Note: Your request was sent to the

RBG_Red virtual server.

Repeat the request with http://web2.training.lab/blue.php and http://web2.training.lab/green.php

30. You can view the hit counts increase in the Content Switching > Policies node or when you open

the content switching virtual server.

http://web2.training.lab/red.php

http://web2.training.lab/blue.php

http://web2.training.lab/green.php

END OF EXERCISE

Exercise 4: SSL Offload

Overview

You want to secure traffic to your web servers using SSL certificates. In this lab, you will create a

certificate and configure NetScaler to offload the SSL transactions while load balancing the Red, Blue and

Green Web servers. SSL Offload is how the NetScaler appliance transparently accelerates SSL

transactions. All SSL processing is performed on the appliance instead of the backend web server. This

reduced workload allows the web server to serve web pages much faster.






4. Microsoft SQL Server 2008: (SQLServer)





Step Action

1. Open the NetScaler Configuration Utility. Navigate to SSL > Create CSR (Certificate

Signing Request


File name: wildcard.req

Key File Name: (Browse > ns-root.key)

Format: PEM

Common name: *.training.lab

Fill all other required fields, but do not put a password.

2.

Navigate to SSL > Manage Certificates / Keys / CSRs.

Step Action

3. Select the wildcard.req file and click Download.

Save the file in C:\Users\administrator.TRAINING\Documents.

Click Close twice.

4. Open another tab in IE and browse to https://192.168.10.12/certsrv .

Login as…

Username: Administrator

Password: Citrix123

5. Select Request a certificate

6. Select Advanced Cert Request.

Then select Submit a certificate request by using a base-64…

https://192.168.10.12/certsrv

Step Action

7. Open the wildcard.req filewith Notepad.exe and copy the contents.

8. Paste the contents into the Saved Request field.

Choose Web Server as the Certificate Template and click Submit.

9. Download a Base 64 encoded certificate (certnew.cer) to the documents folder.

10. Using the NetScaler Configuration Utility, navigate to SSL > Manage Certificates / Keys /

CSRs.

Step Action

11. Click Upload.

Browse to C:\Users\administrator.TRAINING\Documents .

Select the certnew.cer file and upload to the appliance.

Note: the file will be uploaded to the /nsconfig/ssl directory.

12. To install the certificate, navigate to SSL > Certificates > Install.


Certificate-Key Pair Name: wildcard-cert

Certificate File Name: browse (Appliance) to certnew.cer

Private Key File Name: browse (Appliance) to ns-root.key

Click Install.

Then click Close.

14. Navigate to Content Switching > Virtual Servers.

Open the RBG_CSW virtual server and unbind all the content switching policies.

15. Add a new virtual server.

Configure as follows:

Name: RBG_CSW_HTTPS

IP Address: 192.168.10.217

Protocol: SSL

Bind the CSW policies with priorities as shown below.

16. Note that the virtual server is in a down state since it has not certificate bound.

17. Double-click the virtual server and select the SSL Settings tab.

18. Select the wildcard-cert and click Add. Click OK

Note: This binds the certificate to the virtual server. The state is now UP.

19. Browse to https://web2.training.lab and confirm that you are connecting using HTTPs and the

NetScaler is offloading the SSL transactions.

END OF EXERCISE

https://web2.training.lab/

Exercise 5: HTTP header modification

Overview

In today‟s web, applications often require different responses or information sent to backend servers as

part of the HTTP requests/response. For example, when the home page is requested, a different response

is required depending upon the user‟s location, or the language the browser accepts, or simple the type of

browser it is being used to connect to the site.

With the help of rewrite and responder, we can manipulate the parameters on the request or response and

based on certain conditions take a different action. This is especially useful when you want to masquerade

any information return by the server or simply redirect the client connection to a secure site.

In this module, we will explore different examples on how to use the rewrite and responder feature to

perform HTTP to HTTPs redirection, as well as changing the body of the response to ensure all links are

displayed with the correct secure protocol. In addition, we will also configure a simple URL

transformation to hide the application path and also garble some of the parameters returned by the

backend server with the purpose to enhance application security.



1. Linux Server 1 : Apache_MySQL_1 - (GENTOO_1)



4. NetScaler VPX: (NS10_HA1)


6. Windows 7 workstation: (Win7Client)


Step Action

1. We will complete a simple load

balancing configuration to be used in

our rewrite examples. In this lab, we will

configure additional servers and services

for an Apache web server farm.

Open IE and browse to

http://192.168.10.220

Navigate to Load Balancing ->

Servers and configure the following:

Name: GENTOO_3

IP Address: 192.168.10.15

Click Create. Then click Close.

2. Create a service with the following configuration:

Name: GENTOO_3_HTTP_TCP_80

Monitor: TCP

3. Create a Loadbalanced vserver with the following configuration:

Name: HTTP_vserver

IP address: 192.168.10.218

Protocol: HTTP

Port: 80

http://192.168.10.220/

4. Bind the service we created on step 2 to it.

5. Apache_MySQL_3 has been

provisioned with a simple PHP

page that outputs all the server

variables and headers included in

the HTTP request. This page is

served as the default 404 not

found HTML.

For this lab, we will use this

server to visually inspect the

information the backend server

received after the traffic is

processed by the NetScaler

appliance.

In IE, browse to a non-existing

URL on the new

HTTP_vserver.

http://192.168.10.218/nonexist

enturl/

Inspect the headers and

variables to familiarize with the

output.

6. First, we will start with a header insertion to include the CLIENT-IP address in the HTTP

request. This can be accomplished in two different ways:

Using the CLIENT-IP option in the Advanced Properties of the service.

Using a rewrite rule to insert a new HTTP header.

http://192.168.10.218/nonexistenturl/


7. We will start with option 1.

Open the

GENTOO_3_HTTP_TCP_

80 service and select the

Advanced tab.

Under Settings, check the

Client IP option. Fill in the

header name Client-IP.

8. Open a new browser instance

and attempt your request again.

http://192.168.10.218/nonexis

tenturl/

You should be able to see the

“Client-IP” being inserted in

the request.



9. Now, we will attempt to use a

rewrite policy to insert the

same information.

Remove the CLIENT-IP

insertion configuration from

the Settings section of the

Advanced tab.

10. Open a browser and navigate to the same URL to ensure the header is not inserted.


11. Next, create the rewrite action.

Navigate to Rewrite > Actions.

Click on Add and configure the

following:

Name: InserClientIP

Type: INSERT_HTTP_HEADER

Header Name: Client-IP

String Expression: CLIENT.IP.SRC

Click Create.

Then click Close.

12. Next, we need to create a new policy

and bind it to the rewrite action.

Navigate to the Rewrite > Policies.

Click on Add and configure the

following:

Name: InsertClientIP_pol

Action: InsertClientIP

Expression: true


Click Create.

Then click Close.

13. Finally, we need to bind the policy to

the HTTP_vserver.

Double-click the HTTP_vserver and

select the Rewrite (Request) tab.

Bind the InsertClientIP_pol policy

with the default priority.

Click OK to commit the changes.

NOTE: If the rewrite policy does not

show up when attempting to bind,

close the Configure Virtual Server

window and perform a Refresh. Then

attempt the binding again.

14. Select the IE tab in which you browsed

to:

http://192.168.10.217/nonexistenturl

Refresh the window and verify that the

client IP was inserted.

15. Next, we will create a Response Rewrite policy to obscure some of the information sent by

http://192.168.10.217/nonexistenturl

the backend server.

16. To visualize the request and

response headers received,

open a new IE instance and

display the

ieHTTPHeaders.

Note, the add-on is already

installed and enabled.

Navigate to Tools menu

and select Display

ieHTTPHeaders

17. Now, navigate to the IP

Address of the virtual

server.

http://192.168.10.218

You should see the request

and response headers.

18. Take a closer look at the

response headers. Since this

backend server runs

Apache, it includes a Server

header in its response. A

common practice is to

masquerade this information

and include a generic

response.

http://192.168.10.218/

19. We will create a rewrite action to replace the HTTP header.

In the NetScaler Configuration Utility, navigate to Rewrite > Actions and click on Add.

20. Configure the following settings:

Name: ReplaceServerHeader

Type: REPLACE

Expression to choose target: HTTP.RES.HEADER(“Server”)

String expression for replacement text: “MyWebServer” (include the quotes)

Click Create.

Then click Close.

21. Next, create a rewrite policy. Since we need to perform the action on every response, use a true

expression. Navigate to Rewrite > Policies. Click Add.

Configure the following settings:

Name: ReplaceServerHeader_pol

Action: ReplaceServerHeader

Expression: TRUE

Click Create.

Then click Close.

22. Navigate to Load

Balancing > Virtual

Servers.

Double-click on the

HTTP_vserver and select

the Policies tab.

Under the Policies tab,

select the Rewrite tab.

Bind this rewrite policy to

the HTTP_vserver.

Ensure you click the

dropdown arrow and select

the RESPONSE rewrite;

otherwise, the policy will

not be listed.

Click OK.

23. Open a new browser instance and browse to http://192.168.10.218

24. Inspect the response headers. Verify the server header value was replaced.

http://192.168.10.218/

END OF EXERCISE

Summary

Key

Takeaways

The key takeaways for this exercise are:

Rewrite and responder can be used in conjunction to manipulate the data and enhance

application security.

Rewrite policies can modify data on the request and/or response.

Exercise 6: HTTP to HTTPs redirection and

URL body rewrite

Overview

Certain applications require specific requests to occur over a secure connection. Leveraging the responder

module, the NetScaler can issue a redirect to a secure site, ensuring a seamless user experience.

Additionally, the rewrite module can be used to rewrite any HTLM content containing any reference to an

HTTP URI, forcing the connecting client to navigate the site using HTTPs only. In this exercise, we will

configure a responder policy that redirects requests to an alternate URL and continue to setup a rewrite

policy that rewrites any HTTP URIs to force secure browsing.






4. Web Server Blue: (WebBlue)

5. Web Server Green: (WebGreen)

6. Web Server Red: (WebRed)

7. SQLServer



10. Windows 7 workstation: (Win7Client)


Step Action

1. The first step in securing an application is to ensure all requests occur over an encrypted channel.

For this example, we will use a pre-installed web application (PHPMyAdmin) available on the

Linux web server (Apache_MySQL_3). Since this application lives in the “/phpmyadmin”

subdirectory, we will configure a responder action to redirect all request to HTTPs.

Step Action

2. In the NetScaler

Configuration Utility, navigate

to System > Settings >

Configure Advanced

Features and enable the

Responder option.

3. Navigate to Responder > Actions. Click Add.

4. Create a responder action that redirects to a secure URL.


Name: RedirectToSecureSite

Type: Redirect

Target: “https://” + HTTP.REQ.HOSTNAME +

HTTP.REQ.URL.PATH_AND_QUERY

The target specified above ensures that any hostname is redirected regardless of the host header.

Since this expression could potentially create a redirect loop, make sure that you select the

“Bypass Safety Check” option to allow the action to be created.

Click Create.

Then click Close.

Step Action

5. Next, create a responder policy to

trigger the action.

Navigate to Responder > Policies.

Click Add.


Name: RedirectToSecureSite_pol

Action: RedirectToSecureSite

Expression: true

Since this will be bound to

HTTP_vserver, use a “true”

expression.

Click Create.

Then click Close.

6. Navigate to Load Balancing >

Virtual Servers.

Double-click the HTTP_vserver and

select the Policies tab.

Under the Policies tab, select the

Responder tab.

Select Insert Policy and bind this

policy using the default priority.

Click OK.

Step Action

7. Open a browser instance and navigate

to the VIP.

http://192.168.10.218

Use the ieHTTPHeaders to verify the

redirect is triggered.

Why is the page not displayed?

8. Since we do not have a Virtual server listening on port 443, the redirect does not complete

properly. Let‟s proceed to create a new SSL vserver. Navigate to Load Balancing -> Virtual

Servers. Click Add.

9. Create the vserver with the

following configuration:

Name: HTTPs_vserver

IP Address: 192.168.10.218

Protocol: SSL

Port: 443

Ensure that you bind the

same service:

GENTOO_3_HTTP_TCP_80.

http://192.168.10.218/

Step Action

10. Since this is an SSL vserver,

we need to bind a server

certificate.

Select the SSL Settings tab.

Select the wildcard-cert and

click Add to bind this

certificate to the vserver.

Click Create to complete the

configuration.

Click Close.

11. Attempt to test the responder

policy by navigating to the

HTTP URL.

http://192.168.10.218/phpm

yadmin

Since we are not using an

FQDN, a warning is

displayed. Proceed to accept

the warning. The default

content should be displayed

over a secure channel.

(https://...)

http://192.168.10.218/phpmyadmin

http://192.168.10.218/phpmyadmin

Step Action

12. To avoid this SSL warning,

let‟s re-issue the request using

the FQDN that resolves to

the VIP:

http://web3.training.lab/php

myadmin

The redirect should complete

without any warning message.

13. This responder policy will redirect any request to port 80 to 443; however, some applications

hardcode absolute URLs or require special Host headers to serve content. This is especially

troublesome when the application is SSL Offloaded as it could render all the links inaccessible or

the application fails to work.

14. Attempt to login to the

phpMyAdmin application

using the following

credentials:

Username: root

Password: Citrix123

Did the login request work?

You should see that a redirect

diverts traffic directly to the

backend server, effectively

bypassing the load balancer.

http://web3.training.lab/phpmyadmin

http://web3.training.lab/phpmyadmin

Step Action

15. In order to get through the

initial login, we need to

rewrite the redirect request

the backend server is sending

to include the FQDN for the

VIP. To do this, we will use a

Rewrite Response policy.

Observe the “header trace”

captured. The Location

header has the wrong

information.

Step Action

16. Proceed to create a Rewrite Action with the following configuration:

Name: ReplaceLocationHeader

Type: Replace

Expression to choose: HTTP.RES.HEADER(“Location”)

String expression for replacement: “https://web3.training.lab” +

HTTP.RES.HEADER(“Location”).TYPECAST_HTTP_URL_T.PATH_AND_QUERY

The above expression looks for the Location Header value in the response and changes the

hardcoded IP address for the VIP FQDN.

Click Create.

Then click Close.

17. Next, create the rewrite policy.

Navigate to Rewrite > Policies.

Configure the policy as follows:

Name: ReplaceRedirect_pol

Action: ReplaceLocationHeader

Click Create.

Then click Close.

Step Action

18. Bind the rewrite policy to the HTTPs_vserver

load balanced virtual server.

Ensure to select the Response queue, otherwise

the policy will not show up in the list.

19. Attempt to login to the application.

http://web3.training.lab/phpmyadmin/

Is the request redirected to HTTPs?

Does the application complete the login

request?

After binding the previous policies, the

application works as intended. Navigate a few

links to verify correct behavior. Observe the

links on the page.

http://web3.training.lab/phpmyadmin/

Step Action

20. Close the ieHTTPHeaders window.

Click the home icon on the top left side of the

phpMyAdmin site.

Once on the home page, scroll to the bottom

of the page and hover the mouse pointer over

the “here” hyperlink.

There is one more problem with this

configuration. Unfortunately, some of the links

are hardcoded by the application and the URL

includes the backend server IP. Notice the IP

in the URL in the screenshot to the right.

We need to configure a rewrite policy to

modify the response body and replace this

static value for the correct FQDN.

21. Let‟s configure another rewrite policy to adjust

the body.

First, configure the rewrite action as follows:

Name: Rewrite_Body_HTTP_HTTPs

Type: REPLACE_ALL

Expression to choose:

HTTP.RES.BODY(100000)

String expression: https://web3.training.lab

Pattern: http://192.168.10.15

Click Create.

Then click Close.

Note: Choose the response body as the target

text reference. For the body argument, use

100000 characters. This should be plenty to

catch all instances of the pattern to replace.

https://web3.training.lab/

Step Action

22. Create the policy with the following

configuration:

Name: Rewrite_Body_HTTP_HTTPs_pol

Action: Rewrite_Body_HTTP_HTTPs

Expression: true

The true expression will trigger the action on

every instance that matches the pattern. 23. Next, bind the policy to HTTPs_vserver

response queue using the default priority.

Make sure that you select NEXT for the

“Goto Expression” on the first policy,

otherwise the policy with lower priority will not

be evaluated.

24. Test the application one more time by

refreshing the PHPMyAdmin page. The URL

should now be rewritten and the web

application was correctly SSL offloaded

through NetScaler.

END OF EXERCISE

Summary

Key

Takeaways Rewrite policies can be string together to manipulate the request or

response data sequentially.

For some web-apps, deeper knowledge of the application logic is required

to successfully configure the necessary rewrite policies. Additional

information can be inherited from header/network traces and log analysis.

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Revision History

Revision Change Description Date

1.0 Original Version June 2013

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