Cisco Blogs

Cisco Blog > Data Center

ITD: Winner of the Best of Interop 2015

When the Best of Interop 2015 award winners were announced at the Mandalay Bay Convention Center in Las Vegas, the ITD team members couldn’t control their emotions. This team is well known to work in a startup-mode — comes up with new ideas, builds a prototype, demonstrates it to the executives and SEs, goes into execution mode, and delivers a world class solution.

As the leader of this team, I was asked by several media representatives for an interview. Here is an interview by Information Week news desk (watch full-screen for HD):

ITD (Intelligent Traffic Director) is now shipping on Nexus 9k/7k/5k series of switches.

Here is an informative blog on ITD.


Tags: , , , , , , , , , , , , , , , , , , , , , , ,

Interop 2015 : ITD is Best of Interop finalist


ITD (Intelligent Traffic Director) has been selected in Top 3 finalists in the Best of Interop 2015 Data Center category. ITD Delivers:

  • $2 Billion TAM disruptive technology: This technology innovation disrupts today’s $2 Billion TAM for load-balancers, redirection and clustering solutions
  • 100x Scale improvement: The high-end load-balancers today can handle about 200Gbps traffic. ITD can load-balance 20Tbps traffic.
  • 1000x cost-savings for customers: A 40Gbps L4 load-balancer costs about $200k to customers. ITD provides multi-Tbps load-balancing for a fraction of the price.
  • Zero Latency: ITD performs load-balancing, redirection, NAT and access control, all in one-clock cycle in hardware, hence it introduces zero latency.
  • 10x OPEX savings : Order of magnitude reduction in configuration, and ease of deployment
  • Overall CAPEX savings : Wiring, Power, Rackspace and Cost savings
  • 70+ customers interested in deploying within 1 month of shipping.
  • 10x High availability : N + M redundancy, health-monitoring and automatic failure handling
  • $15 Billion install-base can be leveraged: The technology has humongous market capture potential. It works on existing hardware. $15 Billion install-base of Nexus switches is able to use this technology.
  • 30+ patentable ideas: ITD has unprecedented innovations.

Cisco ITD (Intelligent Traffic Director) is a hardware based multi-Tbps Layer 4 load balancing, traffic steering and clustering solution on Nexus 9K/7K/6K/5K series of switches. It supports IP-stickiness, resiliency, 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 has a lot of different types of use-cases. Some of these are:

  1. Create a multi-Tbps Firewall
  2. Create a multi-Tbps Video-cache
  3. Firewall/IPS/IDS/WAF load-balancing.
  4. Web Server load-balancing
  5. Application server load-balancing
  6. Replace WCCP. Redirect and Load-balancing traffic to Web-cache, WAAS, WAE
  7. Traffic steering to VDS/video-cache/Professional Media Network devices
  8. Load-balance to Hadoop/Big-data cluster.
  9. load-balancing to mobile equipment
  10. Load-balancing to Layer 7 load-balancers
  11. Replace legacy features such as ECMP, port-channel, PBR, etc

Recording of the presentation


Tags: , , , , , , , , , , , , , , , , , , , , ,

Cisco ITD is Best of Interop 2015 Finalist

Transforming Cisco switches into highly scalable zero latency load balancers! Cisco Intelligent Traffic Director (ITD) does exactly that and much more!

Cisco ITD  has been selected as Best of Interop 2015 finalist in the Data Center Category. Finalists were chosen from nine categories including Data Center, Mobility, SDN and Cloud Technologies.

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 9K,7K,6K,5K series of switches. Customers do not have to buy any new hardware. It works on all the existing hardware, linecards and supervisors.

Here are some of the quotes from customers, account teams, industry analysts and architects:
“Great milestone Samar Sharma, Mouli Vytla, Rajendra Kumar Thirumurthi  and team! We are very grateful for the work you guys did with pioneering and driving this new solution!”

ITD  helped us scale to 1Tbps of cache traffic in single Nexus 7700 ”

“This feature seems almost too good to be true! I am very excited about it.”

“Customers really enjoyed the time and the subject. They said it was the best presentation of the week at Cisco Live”

“Turns out we likely have a far superior solution in ITD  that we can bring to the table.  One of our web space principles is ‘state is the enemy of scale’ and ITD aligns very well with this mentality without sacrificing too much flexibility or control. It is still early in our conversations but we are confident that ITD will play a strategic role for scaling services”

Click  to find out more! You can also visit Cisco Interop Booth at Interop Las Vegas to find out about Cisco ITD Solution!

Tags: , , , , , , , , , , , , , , , , ,

No Latency Load Balancer in Data Centers

Cisco Intelligent Traffic Director (ITD) is a zero latency multi-terabit layer 4 load-balancer available on 5k/6k/7k/9k. It has support for traffic steering and clustering solution on the Nexus  series of switches.

ITD 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  switches, 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 takes load balancing decision in a single clock cycle of the switching hardware, Hence avoiding latency altogether.

ITD supports IP-stickiness, resiliency, 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 available on Nexus 7000/7700 series in NX-OS 6.2(10) or later. It is available for demo/EFT on Nexus 5k/6k/9k.  ITD is much superior than legacy solutions like PBR, WCCP, ECMP, port-channel, layer-4 load-balancer appliances.

Screen Shot 2015-03-02 at 10.28.21 AM

Note:- ITD is not a replacement for  L7 load balancers



Tags: , , , , , , ,

VXLAN/EVPN: Standards based Overlay with Control-Plane

Given the tremendous interest in VXLAN with MP-BGP based EVPN Control-Plane (short EVPN) at Cisco Live in Milan, I decided to write a “short” technology brief blog post on this topic.

VXLAN (IETF RFC7348) has been designed to solve specific problems faced with Classical Ethernet for a few decades now. By introducing an abstraction through encapsulation, VXLAN has become the de-facto standard overlay of choice in the industry. Chief among the advantages provided by VXLAN; extension of the todays limited VLAN space and the increase in the scalability provided for Layer-2 Domains.

Extended Namespace – The available VLAN space from the IEEE 802.1Q encapsulation perspective is limited to a 12-bit field, which provides 4096 VLANs or segments. By encapsulating the original Ethernet frame with a VXLAN header, the newly introduced addressing field offers 24-bits, thereby providing a much larger namespace with up to 16 Million Virtual Network Identifiers (VNIs) or segments.




While the VXLAN VNI allows unique identification of a large number of tenant segments which is especially useful in high-scale multi-tenant deployments, the problems and requirements of large Layer-2 Domains are not sufficiently addressed. However, significant improvements in the following areas have been achieved:

  • No dependency on Spanning-Tree protocol by leveraging Layer-3 routing protocols
  • Layer-3 routing with Equal Cost Multi-Path (ECMP) allows all available links to be used
  • Scalability, convergence, and resiliency of a Layer-3 network
  • Isolation of Broadcast and Failure Domains

IETF RFC7348 – VXLAN: A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks

Scalable Layer-2 Domains

The abstraction by using a VXLAN-like overlay does not inherently change the Flood & Learn behavior introduced by Ethernet. In typical deployments of VXLAN, BUM (Broadcast, Unicast, Multicast) traffic is forwarded via layer-3 multicast in the underlay that in turn aids in the learning process so that subsequent traffic need not be subjected to this “flood” semantic. A control-plane is required to minimize the flood behavior and proactively distribute End-Host information to participating entities (typically called Virtual Tunnel End Points aka VTEPs) in the same segment – learning.

Control-plane protocols are mostly employed in the layer-3 routing space where predominantly IP prefix information is exchanged. Over the past years, some of the well-known routing protocols have been extended to also learn and exchange Layer-2 MAC addresses. An early technology adoption with MAC addresses in a routing-protocol was Cisco’s OTV (Overlay Transport Virtualization), which employed IS-IS to significantly reduce flooding across Data Center Interconnects (DCI).

Multi-Protocol BGP (MP-BGP) introduced a new Network Layer Reachability Information (NLRI) to carry both, Layer-2 MAC and Layer-3 IP information at the same time. By having the combined set of MAC and IP information available for forwarding decisions, optimized routing and switching within a network becomes feasible and the need for flood to do learning get minimized or even eliminated. This extension that allows BGP to transport Layer-2 MAC and Layer-3 IP information is called EVPN – Ethernet Virtual Private Network.

EVPN is documented in the following IETF drafts

Integrated Route and Bridge (IRB) – VXLAN-EVPN offers significant advantages in Overlay networking by optimizing forwarding decision within the network based on Layer-2 MAC as well as Layer-3 IP information. The decision on forwarding via routing or switching can be done as close as possible to the End-Host, on any given Leaf/ToR (Top-of-Rack) Switch. The Leaf Switch provides the Distributed Anycast Gateway for routing, which acts completely stateless and does not require the exchange of protocol signalization for election or failover decision. All the reachability information available within the BGP control-plane is sufficient to provide the gateway service. The Distributed Anycast Gateway also provides integrated routing and bridging (IRB) decision at the Leaf Switch, which can be extended across a significant number of nodes. All the Leaf Switches host active default gateways for their respective configured subnets; the well known semantic of First Hop Routing Protocols (FHRP) with active/standby does not apply anymore.

Summary – The advantages provided by a VXLAN-EVPN solution are briefly summarized as follows:

  • Standards based Overlay (VXLAN) with Standards based Control-Plane (BGP)
  • Layer-2 MAC and Layer-3 IP information distribution by Control-Plane (BGP)
  • Forwarding decision based on Control-Plane (minimizes flooding)
  • Integrated Routing/Bridging (IRB) for Optimized Forwarding in the Overlay
  • Leverages Layer-3 ECMP – all links forwarding – in the Underlay
  • Significantly larger Name-Space in the Overlay (16M segments)
  • Integration of Physical and Virtual Networks with Hybrid Overlays
  • It facilitates Software-Defined-Networking (SDN)

Simply formulated, VXLAN-EVPN provides a standards-based Overlay that supports Segmentation, Host Mobility, and High Scale.

VXLAN-EVPN is available on Nexus 9300 (NX-OS 7.0) with  Nexus 7000/7700 (F3 linecards) to follow in the upcoming major release. Additional Data Center Switching platforms, like the Nexus 5600, will follow shortly after.

A detailed whitepaper on this topic is available on In addition, VXLAN-EVPN was featured during the following Cisco Live! Sessions.

Do you have appetite for more? Post a comment, tweet about it and have the conversation going … Thanks for reading and Happy Networking!

Tags: , , , , , , , , , , , ,