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ITD: Load Balancing, Traffic Steering & Clustering using Nexus 5k/6k/7k/9k

Cisco Intelligent Traffic Director (ITD) is an innovative solution to bridge the performance gap between a multi-terabit switch and gigabit servers and appliances. It is a hardware based multi-terabit layer 4 load-balancing, traffic steering and clustering solution on the Nexus 5k/6k/7k/9k series of switches.

It allows customers to deploy servers and appliances from any vendor with no network or topology changes. With a few simple configuration steps on a Cisco Nexus switch, customers can create an appliance or server cluster and deploy multiple devices to scale service capacity with ease. The servers or appliances do not have to be directly connected to the Cisco Nexus switch.

ITD won the Best of Interop 2015 in Data Center Category.

With our patent pending innovative algorithms, ITD (Intelligent Traffic Director) supports IP-stickiness, resiliency, consistent hash, exclude access-list, NAT (EFT), VIP, health monitoring, sophisticated failure handling policies, N+M redundancy, IPv4, IPv6, VRF, weighted load-balancing, bi-directional flow-coherency, and IPSLA probes including DNS. There is no service module or external appliance needed. ITD provides order of magnitude CAPEX and OPEX savings for the customers. ITD is much superior than legacy solutions like PBR, WCCP, ECMP, port-channel, layer-4 load-balancer appliances.

ITD provides :

  1. Hardware based multi-terabit/s L3/L4 load-balancing at wire-speed.
  2. Zero latency load-balancing.
  3. CAPEX savings : No service module or external L3/L4 load-balancer needed. Every Nexus port can be used as load-balancer.
  4. Redirect line-rate traffic to any devices, for example web cache engines, Web Accelerator Engines (WAE), video-caches, etc.
  5. Capability to create clusters of devices, for example, Firewalls, Intrusion Prevention System (IPS), or Web Application Firewall (WAF), Hadoop cluster
  6. IP-stickiness
  7. Resilient (like resilient ECMP), Consistent hash
  8. VIP based L4 load-balancing
  9. NAT (available for EFT/PoC). Allows non-DSR deployments.
  10. Weighted load-balancing
  11. Load-balances to large number of devices/servers
  12. ACL along with redirection and load balancing simultaneously.
  13. Bi-directional flow-coherency. Traffic from A–>B and B–>A goes to same node.
  14. Order of magnitude OPEX savings : reduction in configuration, and ease of deployment
  15. Order of magnitude CAPEX savings : Wiring, Power, Rackspace and Cost savings
  16. The servers/appliances don’t have to be directly connected to Nexus switch
  17. Monitoring the health of servers/appliances.
  18. N + M redundancy.
  19. Automatic failure handling of servers/appliances.
  20. VRF support, vPC support, VDC support
  21. Supported on all linecards of Nexus 9k/7k/6k/5k series.
  22. Supports both IPv4 and IPv6
  23. Cisco Prime DCNM Support
  24. exclude access-list
  25. No certification, integration, or qualification needed between the devices and the Cisco NX-OS switch.
  26. The feature does not add any load to the supervisor CPU.
  27. ITD uses orders of magnitude less hardware TCAM resources than WCCP.
  28. Handles unlimited number of flows.

For example,

  • Load-balance traffic to 256 servers of 10Gbps each.
  • Load-balance to cluster of Firewalls. ITD is much superior than PBR.
  • Scale IPS, IDS and WAF by load-balancing to standalone devices.
  • Scale the NFV solution by load-balancing to low cost VM/container based NFV.
  • Scale the WAAS / WAE solution.
  • Scale the VDS-TC (video-caching) solution.
  • Scale the Layer-7 load-balancer, by distributing traffic to L7 LBs.
  • ECMP/Port-channel cause re-hashing of flows. ITD is resilient, and doesn’t cause re-hashing on node add/delete/failure.

Documentation, slides, videos:

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Please note that ITD is not a replacement for Layer-7 load-balancer (URL, cookies, SSL, etc). Please email: for further questions.

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Pulsant Accelerates Business Transformation with Cloud solutions from Cisco and F5

Data Centers and Clouds are all about applications. The efficacy of a data center or cloud deployment is a function of how quickly applications can be stood up, scaled or de-commissioned as required. As new architectures continue to evolve, data center and cloud architects are constantly on the lookout for innovative ways to further simplify operations, lower costs, increase responsiveness and provide flexibility of consumption models.

In this context, I’d like to take the opportunity to profile Pulsant – a cloud service provider from the United Kingdom. They provide colocation services across 10 data centers with managing hosting and innovative hybrid services that are continually evolving.

A short while ago, I had the pleasure of having Martin Lipka who heads the Pulsant network architecture team participate in a talk with me sharing deployment insights with customers at the F5 conference in Edinburgh. He talked about the simplicity of Cisco’s Application Centric Infrastructure (ACI), and the synergy with F5’s BigIP and BigIQ offerings down the line. For the benefit of the broader humanity that was not in the room with us, I requested him to sit down again and distill some of his views. Martin was kind enough to oblige and shared his insights on diverse topics including how he expects data center architectures to evolve, candidly confessing why he was wrong about automation trends and how he feels the job roles will morph in the coming years. Interestingly, some of his sentiments were also echoed by Stefaan Hinderyckx, Network and Security Director of Dimension Data Europe. Stefaan is not in this video, but he had joined our session as well and it was good to see everyone excited about the possibilities of network, security and data center transformation.

A fresh case study from Pulsant is also posted here.

Also, at the same conference, I was invited to sit down with F5 EVP Dave Feringa and SVP Calvin Rowland along with my colleague Patrick Schmidt who’s the Managing Director overseeing the EMEA region, where we discussed the partnership, momentum with Cisco ACI and scaling our joint marketing activities.

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How you integrate Network Services matters

Guest post from Lori Mac Vittie (@lmacvittie) from F5 Networks 

How you provision all the network things matters

Polymorphism is a concept central to object-oriented programming. The notion of polymorphism is used to extend the capabilities of a basic object, like a mammal, to specific implementations, like cats or dogs or honey badgers, even though they don’t care about such technical distinctions. A good example of this is cats and dogs, which are both of the type “mammal” but that “speak” in a different voice.


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ITD: Load Balancing, Traffic Steering & Clustering using Nexus 5k/6k/7k


Data traffic has grown dramatically in the recent years, leading to increased deployment of network service appliances and servers in enterprise, data center, and cloud environments. To address the corresponding business needs, network switch and router architecture has evolved to support multi-terabit capacity. However, service appliance and server capacity remained limited to a few gigabits, far below switch capacity.

Cisco Intelligent Traffic Director (ITD) is an innovative solution to bridge the performance gap between a multi-terabit switch and gigabit servers and appliances. It is an hardware based multi-terabit layer 4 load-balancing, traffic steering and clustering solution on the Nexus 7000 and 7700 series of switches.

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ACI Walkabout at CiscoLive 2014, San Francisco

In a few days at the Moscone Center in San Francisco, we will be celebrating the 25th anniversary of Cisco Live. This year we are expecting record attendance exceeding 20,000 participants, 9 amazing keynotes, 600 sessions, live demos at world of solutions, big analyst and partner presence, and last but not least, the opportunity for you to meet and network with top minds in high-tech. If you are new to Cisco Live and feel overwhelmed by the grandness of the event, let me assure you that you are not alone.  I have been there before. I have set out in this blog to give you an easy walkabout of Cisco Datacenter highlights, particularly the Cisco ACI key activities over the duration of the event.

Much like you I will also be eagerly looking to attend John Chambers’ majestic keynote that starts the proceedings on Monday, May 19. John in his unique style will lead with the Theme “Tomorrow Starts Here” covering leading industry trends such as Internet of Everything (IOE), Fast IT, and Application Centric Infrastructure (ACI) among many others. So, do not miss this opportunity. I want to shift gears and take you on a fast cruise of Cisco Data Center and Cisco ACI highlights at the event.


In less than a year since the announcement, Cisco ACI has taken the industry by storm with a large customer base  and several of the industry’s key partners such as Microsoft, Red Hat, Citrix, F5, et al endorsing and building joint solutions. There is so much excitement around ACI at this year’s Cisco Live. I want to give a structure to how I am planning to cover the topic in this blog. Essentially, I consider them as Cisco-led and Partner led.

Cisco has a packed agenda of ACI activities and announcements. Cisco APIC, which enables ACI Fabric mode on Nexus 9000 networks, will be available this summer along with a robust Go-To-Market (GTM) strategy that includes additional eco-system partners, Cisco Validated Designs (CVD), additional platform support and leading-edge hardware innovations across the portfolio. We are also introducing two new additions to the existing portfolio of Nexus 9000 to meet scalability, flexibility and performance requirements of standalone and ACI mode deployments.

Executive ACI speaking sessions feature prominently this year with Cisco President Rob Lloyd’s session “Infrastructure for the Agile Enterprise” keynote, May 20, 10 AM, at the North Hall.  Rob’s keynote also features Soni Jiandani, who will present how ACI delivers agility. Rob Soderbery and Soni Jiandani are presenting a technology trends keynote (GENSK 1109) on May 21, 8.30 am, titled “Fast Track to Fast IT: Cisco’s Application Centric Infrastructure”, another choice from a catalog of exciting offers.

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