Home > Articles > Web Services > Cloud Computing

  • Print
  • + Share This
Like this article? We recommend

Extended Scenario: Accessing Virtual Machines on a VLAN

Provisioning virtual machines on a private VLAN in the cloud gives you far greater security than on the open Internet. This technique is similar to deploying physical machines in your own data center. The machines won't be visible from the Internet and therefore are protected from many threats. Just as servers in a private data center must be accessed using a private connection to the data center, virtual machines provisioned on a VLAN must be accessed through a special connection. This connection is usually provided by a server with two IP addresses, one on the Internet and the other on the VLAN. You must also have a way of routing network traffic from the Internet to the VLAN. If you wanted to route traffic from many users to a web server, you would use a firewall to route the traffic. However, in our scenario we only want to route traffic from the owner of the virtual machine, so we'll use SOCKS.

To complete this scenario, perform the following steps:

  1. Discover the available VLANs.
  2. Allocate an IP address on a VLAN.
  3. Create a SOCKS Proxy virtual machine with two IP addresses.
  4. Provision a virtual machine instance on the VLAN.
  5. Verify access to the VLAN:
    1. Start PuTTY with the SOCKS proxy option.
    2. Access both virtual machines.

Figure 8 shows the configuration.

Figure 8 Accessing a virtual machine on a VLAN with SOCKS.

We'll demonstrate how to do this with the SCE command line, but it's also possible with the web portal.

Step 1: Discover the Available VLANs

You can discover the VLANs available in SCE with this command:

> ic-describe-vlans.cmd -u <user id> -w <passphrase> -g <key file>
Executing action: DescribeVLANs  ...
. . .
ID: 288
Name: Private VLAN Singapore
Location: 141
Executing DescribeVLANs  finished

We'll use the VLAN with ID 288 in the Singapore data center (location ID 141), which we found from the command output above.

Step 2: Allocate an IP Address on a VLAN

The next step is to allocate an IP address on the selected VLAN. To do that, we need to find the address offering for private IP addresses in Singapore, for which we use the describe-address-offerings command:

> ic-describe-address-offerings.cmd -u <user id> -w <passphrase> -g <key file>
. . .
ID: 20027868
Location: 141
Price: $0/UHR
. . .

The command output shows that the address offering ID is 20027868.

The next part is to allocate the IP addresses. We can do that with the allocate-address command:

> ic-allocate-address.cmd -u <user id> -w <passphrase> -g <key file> -L 141 -O 20027868 -x 288
Executing action: AllocateAddress  ...

In this command, the -L argument is the data center ID, -O is the address offering ID, and -x is the VLAN ID.

The address will take a little while to be allocated. We can check the status of the IP address-allocation process with the describe-addresses command:

>ic-describe-addresses.cmd -u <user id> -w <passphrase> -g <key file>
ID: 277993
InstanceId: null
State: FREE
Location: 141
Owner: <user id>
. . .

The address must be in the FREE state before we can use it. Note the ID of the IP address; we'll use it in the next step.

To perform the equivalent action in the SCE web portal, navigate to the Account tab and click the Add IP button. A dialog like the one in Figure 9 will appear.

Figure 9 Allocating an IP on a VLAN by using the SCE web portal.

Step 3: Create a SOCKS Proxy Virtual Machine

We'll use a server running RHEL 6.2, with secondary IP address on the VLAN, and primary IP address on the public Internet to act as the SOCKS proxy. The particular server that we use will be configured as a firewall. The image name in the SCE image library is "IBM Firewall Image on Red Hat EL 6 32-bit PAYG." It's configured with more strict security than other images, which is appropriate for use as an entry point into a VLAN. All unnecessary software has been removed and unnecessary services disabled.

> ic-create-instance.cmd -u <user id> -w <passphrase> -g <key file>
 -t "COP32.1/2048/60" -n SOCKSProxy -k 20036705 -c <my key> -m "{se
condary.ip.0:<address ID>,root_user_password:***}" -L 141
Executing action: CreateInstance  ...
The request has been submitted successfully.
1 instances!
ID: 266635
Name: SOCKSProxy
Hostname: vhost0677
InstanceType: COP32.1/2048/60
Secondary IP(s):
KeyName: <my key>
. . .

In the command above, the -t argument is the instance size, -n is the instance name, -k is the image ID, -c is the key name, -m is the ID of the secondary IP address, and -L is the data center ID.

After executing the command above, wait for instance to be provisioned.

Figure 10 shows the screen from the SCE web portal.

Figure 10 Provisioning the SOCKS proxy with the SCE web portal.

Use the ic-describe-instance command to find the provisioning status and public IP address. After the instance has been provisioned, the public IP address will be enabled, but the secondary IP address will not. To enable the secondary address, use the Linux ifup command:

$ sudo /sbin/ifup eth1

You can check the status of the network interfaces with the Linux ifconfig command. Follow the same steps as in the basic scenario to enable the firewall.

Step 4: Provision a Virtual Machine Instance on the VLAN

In this step, we'll create the virtual machine that we want to access. It will be RHEL 6.2 with a primary IP address on the VLAN. Following is the command to provision the virtual machine:

> ic-create-instance.cmd -u a.user@cn.ibm.com -g mykey.ext
 -w unlock -t "BRZ64.2/4096/60*500*350"
 -n ServerVLAN -k 20025211 -c july26 -x 288 -L 141
Executing action: CreateInstance  ...
The request has been submitted successfully.
1 instances!
ID: 266635
Name: ServerVLAN
Hostname: vhost0677
InstanceType: BRZ64.2/4096/60*500*350
KeyName: <my key>
. . .

In this command, the -t argument is the instance size, -n is the instance name, -k is the image ID, -c is the key name, -x is the VLAN ID, and -L is the data center.

Step 5: Verify Access to the VLAN

Steps 5a and 5b are the same as steps 2 and 3 of the basic scenario. For starting PuTTY with the SOCKS proxy option, see step 2 of the basic scenario ("Step 2: Start PuTTY with the SOCKS Proxy Option"). To access both virtual machines, see step 3 of the basic scenario ("Step 3a: Start the Web Server and Configure the Firewall").

To verify access to the VLAN, enter the address of the virtual machine on the VLAN. Test with and without proxy settings in the browser. Figure 11 shows the results. Notice that you can see the private IP now, even though you're accessing the virtual machine over the Internet. Notice that the IP address in the web browser is a private IP that is not visible on the Internet.

Figure 11 Verifying access to the VLAN.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020