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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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#CiscoChampion Radio S2|Ep 17. Cloud and Metacloud with Peder Ulander

CiscoChampion2015200PX#CiscoChampion Radio is a podcast series by Cisco Champions as technologists. Today we’ll be talking about all things upcoming in the cloud universe with Cisco Vice President of Cloud Services Peder Ulander.

Listen to the Podcast.

Learn about the Cisco Champions Program HERE.
See a list of all #CiscoChampion Radio podcasts HERE.
Ask about the next round of Cisco Champions nominations. EMAIL US.

Cisco SME
Peder Ulander, @ulander — Cisco VP Cloud Services Marketing

Moderator
Kim Austin (@ciscokima) — Collaboration Technology Group

Highlights
Do enterprises need a cloud computing strategy?
What do we mean by “digitization”?
How is digitization the next evolution of Cloud
What is Intercloud and where is it going?
Where is Cisco with OpenStack?
Maintaining and documenting security controls
Containerization Read More »

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So You Want to be a Network Engineer. Here’s Where You Should Start!

First lets talk about what a Network Engineer is. According to The Free On-line Dictionary of Computing. Retrieved April 27, 2015, from Dictionary.com website a Network Engineer is:

“A high-level LAN /WAN technician who plans, implements and supports network solutions between multiple platforms. A network engineer installs and maintains local area network hardware and software, and troubleshoots network usage and computer peripherals.”

Network Engineers can wear many different hats. I believe the more “Traditional” Network Engineers mainly work on devices such as Routers, Switches, Firewalls, Wireless Access Points and Controllers, Load Balancers, Intrusion Detection and Prevention Systems as well as some server maintenance involving virtualization and network management software. Next we should discuss the overview of the differences between Network Engineering and Administration. Keep in mind I am just talking from an industry general view/standpoint. Some companies may not differ between the 2 titles. Engineers and Admins tend to share a lot of responsibility when it comes to maintaining and troubleshooting a network. The dividing line seems to be in the design/installation area with the bulk of this work generally being done by the more “experienced” engineers. Admins usually fall under the NOC (Network Operations Center) which in large companies/agencies is usually staffed 24x7x365. I have also seen the difference broken down into tiers when it comes to troubleshooting escalation. Network Admins usually fall in the Tier 1-2 range with Engineers being considered Tier 3. Read More »

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SDN – A Cisco Champion’s perspective

Software defined networking (SDN for short) is going to be an important technology that will change the way we do networking. But what is SDN today and even more important, what is it going to be?

When you start reading about SDN as a network engineer, you ask yourself what your future job will look like. Will you still be a network engineer as we know you today, or a network developer, with a focus on scripting and programming your network? In my opinion, the reality will be somewhere in between. But no one can tell you today what impact SDN will have on your daily work tomorrow. Read More »

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#CiscoChampion Radio S2|Ep 16. CCIE Wireless Exam Updates

CiscoChampion2015200PX#CiscoChampion Radio is a podcast series by Cisco Champions as technologists. Today we’ll be talking about CCIE Wireless exam updates with Cisco CCIE Program Manager Erik Vangrunderbeek, Cisco Engineering Technical Leader Jerome Henry, Cisco Distinguished Systems Engineer Stephen Orr, and Cisco Consulting Systems Engineer Carlos AlcAntara.

Listen to the Podcast.

Learn about the Cisco Champions Program HERE.
See a list of all #CiscoChampion Radio podcasts HERE.
Ask about the next round of Cisco Champions nominations. EMAIL US.

Cisco SMEs
Erik Vangrunderbeek, Cisco CCIE Program Manager
Jerome Henry, Cisco Engineering Technical Leader
Stephen Orr, Cisco Distinguished Systems Engineer
Carlos AlcAntara, Cisco Consulting Systems Engineer

Cisco Champion Guest Hosts
Samuel Clements, @samuel_clements, Mobility Practice Manager
Andrew vonNagy, @revolutionwifi, Mobility Architect Read More »

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