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To flow or not to flow?

NetApp’s newest storage operating system, clustered Data ONTAP (cDOT), leverages a backend of Cisco Nexus switches for it’s cluster interconnect network.

When configuring the switch/cluster ports for use with cDOT, the best practice is to turn flow control off as per TR-4182. In fact, that happens to be the recommendation for normal data ports as well. Why is that? Before we get into that, let’s cover the basics…

What is flow control?

Flow control is a mechanism used to help manage the rate of data transfer between two devices. This is done to help prevent a source evice from overwhelming a destination device by sending more packets than the destination can handle. These scenarios can occur if a source device is faster than the destination device (CPU, RAM, NIC, etc). This can also happen if the source is intentionally trying to flood the destination via a malicious Denial of Service (DoS) attack.

Flow control can be enacted for send or receive packets, or both. It can be hardware or software based. It can occur at multiple layers of the OSI model

For a real world analogy to flow control, think of how dams work. A dam will be installed to control the flow of water on a river, usually to create lakes or reservoirs. Dams can be used to adjust the water flow to prevent flooding, depending on rainfall. Network flow control does pretty much the same thing – it prevents data floods. Read More »

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Bringing Up a New Branch Site the Easy Way with Prime Infrastructure – Part 4

Last week, I went through application assurance with Cisco Prime Infrastructure. Today, as the 4th post of a 5-part blog series, I’ll go into troubleshooting for your branch site with Prime. Again, as a quick recap, here’s my blog series on how to set up networking with Prime for a new branch site.

WAN deployment – blog 1
Converged wired and wireless  – blog 2
Application performance – blog 3
Troubleshooting – (this blog)
Network health – blog 5
 steve song blog 4 pic 1

By now, your new branch site is in perfect condition with Cisco IWAN, wired and wireless Converged Access, as well as application assurance all working as designed. But you need to be prepared to start troubleshooting if something goes wrong. Every user who runs into network issues means productivity loss.  Every minute of a down network causes a significant amount of business loss. Fortunately, Cisco Prime Infrastructure gives you many tools, so you can achieve speedy problem resolution and provide outstanding user experience.

Here’s a Prime troubleshooting success story that a customer told me. It’s a hospital in Dallas, Texas. Keeping their wireless network running was a critical business priority because the medical staff depended on it for communications and patient care. One day, nurses reported intermittent wireless problems in a room. You know, intermittent problems can be hard to troubleshoot. When you are ready to diagnose the problem, the symptoms may or may not exist anymore. Using Prime, their networking team was able to narrow down to a laptop which was always present when the wireless problems occurred. As it turned out, it was doing heavy and unauthorized live streaming which hogged the wireless bandwidth. The owner was immediately notified to stop streaming. Problem solved and case closed. Read More »

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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.

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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

 

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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.

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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!

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Automated PBR and Route Health Injection with RISE

RISE is an innovative architecture that logically integrates an external service appliance such as Citrix NetScaler or the Cisco Prime NAM so that it appears & operates as a service module within the Nexus 7000 Series switches.
RISE integration with the Citrix NetScaler provides features like Route Health Injection (RHI) and Automated PBR (APBR) which allow easy configuration to redirect client and server traffic to the load balancer.
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Automated Policy Based Routing (APBR)
Existing solutions to have server traffic return to the load balancer are Source NAT and PBR. Using Source NAT causes applications (server) to lose the visibility to client IP, burning IP address pool for Source NAT configuration and manual configuration. Policy Based Routing (PBR) requires complex initial configuration from the user (susceptible to human errors), configuration updates when a server is added or removed which can be cumbersome as the number of network devices and servers/VIPs grow.
  • Auto PBR eliminates the need for Source-NAT or manual PBR configuration in an one-arm mode design of load balancers
  • Preserves client IP visibility for applications/servers without the need for manual PBR
  • APBR feature allows the NetScaler to program policies on the N7K server-facing interfaces to redirect return traffic to the NetScaler appliance set up in one-arm mode
  • NetScaler passes information about real servers to N7K via the RISE channel and a policy is applied on the N7K interface through which the real server can be best reached
  • Since it is desirable to change the SRC IP to VIP for the return traffic, the APBR policies redirect traffic to the NetScaler IP without modifying the packet
  • The NS appliance will then direct the packet to the client by changing the source IP to VIP
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Please reach out to nxos-rise@cisco.com for more information on RISE features.
Resources

RISE At A Glance white paper: http://www.cisco.com/c/dam/en/us/products/collateral/switches/nexus-7000-series-switches/at-a-glance-c45-731306.pdf

RISE announcement blog: http://blogs.cisco.com/datacenter/rise

RISE Video at Interop: https://www.youtube.com/watch?v=1HQkew4EE2g

Cisco RISE page: www.cisco.com/go/rise

 

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