Home > Articles > Cisco Network Technology > General Networking > Network Security Inside and Out: An Interview with Arvind Durai and Ray Blair

Network Security Inside and Out: An Interview with Arvind Durai and Ray Blair

  • Article is provided courtesy of Cisco Press.
  • Date: Jul 1, 2009.


  1. Network Security Inside and Out

Article Description

Arvind Durai and Ray Blair talk with Linda Leung about the changing face of firewalls, whether perimeter security is dead, and how traditional security products fare against disruptive technologies

Like this article? We recommend

Cisco Secure Firewall Services Module (FWSM)

Cisco Secure Firewall Services Module (FWSM)


Network security is paramount to safeguarding corporate data. Network security vendors are challenged to create products that protect networks from existing external and internal threats, defend against new and emerging hacking methods, and be easy for network administrators to manage and not cost an arm and a leg.

I asked Cisco security experts and co-authors of Cisco Secure Firewall Services Module (FWSM), Arvind Durai and Ray Blair, about the landscape for enterprise security. We discussed the changing face of firewalls, whether perimeter security is dead, and how traditional security products fare against disruptive technologies such as mobility, unified communications, virtualization.

Arvind Durai holds the CCIE Routing & Switching and CCIE Security certifications and is a network consulting engineer for Cisco Advanced Services, working on large enterprise networks for network designs. Triple CCIE (R&S, Security, and Service Provider) Ray Blair is a Cisco consulting systems architect, working primarily on security and large network designs.

Linda Leung: Cisco's legendary PIX firewall in July goes into "end of software maintenance releases" and the end of support/end of life is scheduled for July 2013. How successful has the migration program to ASA 5500 Series been, and what are the major differences that network administrators need to become familiar with?

Arvind Durai: Cisco PIX Security Appliance was the flagship of Cisco firewalls for many years. The introduction of ASA firewall was to change the Cisco firewall flagship. ASA uses the Adaptive Security Algorithm similar to PIX. In the field, migration from PIX to ASA started taking place few years back. The migration is seamless from the rule-set specification because the security concept from the architecture is the same in both the product lines. Customers are encouraged to migrate to Cisco ASA 5500 Series Adaptive Security Appliances. Built on the same software foundation as Cisco PIX Security Appliances, the Cisco ASA 5500 Series offers more robust firewall and IPSec VPN capabilities, as well as many additional benefits, including:

  • Significantly better performance and scalability
  • Secure Sockets Layer VPN support (including clientless, portal-based remote access)
  • Advanced unified communications (voice/video) security
  • A modular design that allows you to add features such as intrusion prevention, antivirus, antispam, antiphishing, and URL filtering

Migration to the Cisco ASA 5500 Series is straightforward. Customers can take advantage of their knowledge and investment in Cisco PIX Security Appliances, because there are essentially no major changes in user interface, operations, or training.

Ray Blair: Couldn't have said it better myself!

LL: Cisco MARS (Monitoring Analysis and Response System) is another solid workhorse in Cisco's security portfolio. However, some customers say the product is in need of some fine-tuning. Specifically, an updated GUI, improved incident management, and improved interoperability with third-party network analyzers. What's the roadmap for MARS, and will customers get these improvements?

AD: Cisco MARS is solid security gear and provides security monitoring for network devices and host applications. Security monitoring with MARS improves productivity and efficiency in threat mitigation by greatly reducing false positives. The Cisco MARS provides an end-to-end topological view of the network, which helps improve threat identification, mitigation responses, and compliance. Cisco always strives to improve its product line based on the impact seen in the user community. MARS has several new enhancements and features; some of the areas are GUI, report generation, and interoperability with other products.

RB: Management products are some of the most susceptible to feature lag. Given the numerous devices, new feature/functionality, interoperability, and so on, it is difficult to keep up-to-date with every product on the market. With a finite number of resources, the business unit needs to prioritize where the attention will be focused. Make your local Cisco account team aware of the features that you need, so they can be appropriately prioritized.

LL: Switching from one vendor's gateway firewall to another is a laborious task that could take a minimum of six months because vendors have different access-control rules. What services are there available to make this task less daunting?

AD: Conversion from one vendor firewall to another is always a detailed task where conversion of rules takes a lot of effort. Cisco Security Conversion Tool (SCT) converts other vendors' rule sets to Cisco ASA or FWSM (Firewall Services Module) rule set is a good tool to use for fast conversion of the rules. It is always advised to verify the converted rule set and test in a pilot prior to deployment in the live network.

RB: I certainly agree that firewall conversion is a laborious task. In many cases, this is due to poor firewall documentation. Many customers permit or deny traffic on a temporary basis or to troubleshoot a problem. You may have firewall administrator changes or other change of ownership that can also cause challenges with documentation. There are tools to help with the migration from one firewall to another, but there is no substitute for good documentation, especially if you are hiring someone else to perform the task.

LL: A few years ago, "de-perimeterization" was a popular buzzword. It called for businesses to do away with hardened borders and to instead have different kinds of security appliance at different points of the network. Organizations were supposed to focus on providing encrypted transport and authenticated access to internal data, and ultimately there would be a global, data-level authentication standard. Was this a viable vision and how far along are we?

AD: The perimeter security is still there in the enterprise network but the role and functions of the perimeter security is shifting. Network virtualization uses different virtualization techniques to support IT service virtualization, and it's a key driver in today's enterprises. The virtualization effort needs to tie and extend security for various enterprise layers. Security segregation and extension of these zones on an enterprise level is common. Firewall and security gear placement now is in the data center space, a remote office space extending the same principle of virtualization. By this, the functionality of perimeter firewall for the enterprise has changed from granular rule set to more enterprise specific broader rule sets. The granular rule set is slowly taken care of based on service virtualization in the network.

RB: Encrypted transport and authenticated access is a great solution for remote users, but implementing this in a campus environment is wrought with challenges. For example, users on the LAN expect the applications to perform quickly and this usually requires additional hardware to off-load the encryption function, consequently increasing the cost. Client devices now may require additional software for encryption, which adds to the administration of the desktop. Lastly, when troubleshooting application issues, a sniffer is almost useless since visibility into the data portion of the packet is obfuscated, consequently adding to the complexity of supporting any encrypted applications on the network.

With hardware now available that supports 802.1ae (link security), the need to encrypt from the application will decrease. Data can still be encrypted between devices, consequently minimizing "sniffing" on the network, but a network administrator still has the capability to capture unencrypted traffic from a network device. The ability to authenticate users, devices and the posture of those devices continues to improve in functionality and performance through the use of the NAC (network-access control) appliance. With the combination of a virtualized network, the capabilities of adding security without a tremendous burden from a management perspective is within reach today.

LL: Independent security experts say traditional security tools, such as antivirus and signature-based intrusion-prevention systems, fail to protect against disruptive technologies, such as mobility, unified communications, virtualization and polymorphic malware. Do you agree? How should we best protect these new technologies?

AD: I believe security cannot only be provided by firewall, encryption, or any one device. Security needs to be end-to-end for any system. Security architecture is "key" to protect a system and needs to cover all necessary elements from monitoring, incident response, policy enforcement, data traffic encryption, network access control, security for data storage etc. Cisco SAFE architecture goes through various elements that are important from the network perspective and helps protect the infrastructure against new threats and adapts to secure new services.

RB: Signature-based devices certainly have their challenges when it comes to disruptive technologies. Given that challenge, they are not useless devices. Security is not about a single component, but it's a collection of devices integrated into the network infrastructure that help maintain security. In building a secure network, the limitations of each device need to be considered; other areas that need to be addressed are security policies, physical security, disaster recovery, and so on.

LL: What are your thoughts on endpoint security products that combine traditional network security functions with network-access control and systems management capabilities, such as configuration control, patch management? Is it wise to put all your security eggs in one basket?

AD: My take is to consider security from the system level. The security at the edge is very important to enforce the trust boundary for a security infrastructure. This does not mean the elements for traditional security is replaced. The role of each element in the security architecture plays a unique function. The rules and application of policies will become more distributed covering multiple elements in the security architecture. One system cannot replace the whole security architecture. Consolidation of a couple of elements in a device is certainly possible and helps to improve the manageability of the solution and lowering the operational cost.

RB: Security is almost always directly proportional to complexity; the more secure, the more complex. Finding ways to reduce the complexity through combined security products on the endpoints can be a great solution, but is something that needs to be addressed by every organization.

LL: What's Cisco's view of how end user/traffic security will be managed in 5 years?

AD: At Cisco, I am excited to see the security architecture evolving for user/traffic security. As the enterprise architecture is converging, security architecture will include various elements of network from edge, perimeter, and virtualization of zones based on service virtualization. There is just not one answer for security. Security will have various elements to enforce, protect and monitor. These elements will be customized on the lines of business and by the security architects keeping the overall principles of security architecture. To manage this architecture, reduce operations, and provision cost, all these elements need to interact with one another. Cisco impacts at these various layers of the security architecture will be more prominent to achieve a converged architecture.

RB: If my crystal ball worked that well, I would be a wealthy individual. Given the history of security architectures, I would speculate (clouds in the crystal) that infrastructure components and end user security would be much more closely aligned. Leveraging the collective computing power of workstations to immediately address security vulnerabilities, unique user roles/responsibilities per device, integrated encryption, etc...

LL: Final question: what will you be doing at Cisco Live?

AD:I will be presenting Advanced WAN Design Topics (TECRST-2003), an eight-hour tech tutorial session. The session will cover Enterprise WAN design principles as well as focus on advanced topics including highly available WAN design, network virtualization options for the WAN, IP multicast considerations, application intelligence and design components for WAN QoS.

RB: Unfortunately, I am not attending this year.

Linda Leung is an independent writer and editor in California. Reach her at leungllh@gmail.com.

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press 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 Cisco Press 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@ciscopress.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 Cisco Press. 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.ciscopress.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