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

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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
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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.

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