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One of my customers is planning to migrate his data center network to Rapid Spanning Tree. Although RSTP is a well established technology, it will be new to his site. Cisco has a migration discussion here: Spanning Tree from PVST+ to Rapid-PVST Migration Configuration Example

Building on that discussion, I wanted to gather some metrics for him. What would be the impact of moving the access switches first, then the core switches?

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Cisco has courage. The world of IT is changing, and rather than cling to the successes of the past, Cisco is trying to embrace and shape the future.  Bruce Klein quoted Peter Drucker as saying "The best way to predict the future is to create the future." It’s clear that Cisco is trying to do just that.  In order to pull it off, Cisco and its partners will have to change more in the next year than they have in the previous three years. John Chambers says that at least 1/3 of companies will not survive 25 years.

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Posted by on in Data Center

Recently, Cisco generously provided a briefing to the CiscoChampions, updating the group with new details about Cisco ACI. The presentation was NDA until April 2, I presume coordinated with announcements to be made at InterOp. The biggest new item I noticed was OpFlex. I'll tell you what I know about OpFlex below, somewhat below the tantalizing diagram. I'll be posting this quickly in the morning, then off to various tasks. When I can, I'll look at any announcements and apply corrections if necessary. 

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Looking Ahead to the Cisco Partner Summit 2014!

The Cisco Partner Summit 2014 is almost upon us, and I’m looking forward to a great week there.  Cisco has consistently strong events, ones that are worth making the time to participate in.  I haven’t heard numbers, but I have the impression that the in-person event is shrinking in favor of virtual attendance.  If you have the chance to go in person, you should take it, but I encourage anyone at a Cisco Partner who wants to see the future to join us by using the Cisco Virtual Partner Summit 2014.

Here’s what I’m looking forward to:

Tagged in: ciscops14

I'm speaking at both Enterprise Connect and Interop again this year. The Enterprise Connect conference is March 17 - 20, 2014. I'll be presenting the very successful session titled How to Keep Video from Blowing Up Your Network. This session has been well attended and has received very good reviews at past conferences. In it, I discuss the sources of video traffic, their characteristics, and how to identify video traffic on the network. There are some pragmatic mechanisms that can be employed to reduce the amount of work that is needed to identify video traffic. I will then discuss how to handle traffic that you do want, such a a CEO's video conference, and video that you don't want, like video movie downloads or streaming video. There are two approaches to handling video that you don't want and I discuss both, with an example that we have deployed with customers.

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Posted by on in Data Center

20140307-fig01Here in the Baltimore-DC area, we can't wait for Spring to end all the cold snowy weather we've been having. We don't quite see the signs yet. We need a new groundhog! Anybody want a used one?

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Posted by on in Data Center

20140305-nexus9000Ever since I heard that the Nexus 9K has 50% less code, I've been wondering what features were removed from the code. So I did my best to figure it out, since I haven't seen a detailed features list from Cisco yet (early days and all that). I've also noticed that in general the Nexus team historically has put out long lists of supported features, leaving me thinking "yes, that's great -- but what is NOT on the list?" Anyway, the primary focus here will be what features the N9K supports today. We'll get to that after a motivational detour (or some might say "pre-ramble"). 

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Posted by on in Data Center

20140304-fig01The Cisco announcement last November of Insieme ACI and Nexus 9K hardware gave us a plethora of choices, and left many wonder what Nexus box they should use, and where. It behooves us all to understand the Cisco Nexus product positioning, since they aren't cheap, and we don't want to paint ourselves into a corner with the wrong purchase. That's particularly important for consultants and Cisco resellers providing purchasing recommendations. This blog lays out the major considerations in picking which Nexus platform to buy, and where to use it in your datacenter. 

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20140303-fig01I get the strangest looks when I talk about POAP and ask people "Why Aren't You Using It?" Admittedly, it doesn't help that I like to pronounce acronyms like words, and POAP comes out sounding like "Pope" or perhaps "Poe-App". Perhaps it will help if I mention that POAP is the Nexus equivalent of Auto-Install for Cisco routers. I suspect that aside from not being aware of POAP, a lot of people haven't looked into what POAP can do for them. As with Auto-Install, you might have looked and found that it seemed complex. Yes, it's easy enough to paste in the configuration from the CLI, one less thing to troubleshoot. 

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Posted by on in Data Center

20140228-fig01The good news is that there are lots of ways to capture packets on Cisco device. That's also the bad news: there are many different ways to do differing degrees of capture, depending on the device type! No doubt this is a side effect of the independent and somewhat Darwinian nature of product groups within Cisco. I'm writing this blog as I've been exploring the packet capture side of Cisco devices as CCIE recert prep (EPC, WireShark Trace Analyzer). Packet capture is not a feature I use very often, so there's been progress that I (and you!) might not have been aware of. 

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Posted by on in Data Center

I presented a Cisco Mid-Atlantic Users Group session on "Datacenter Topics" today. It covered NSX, DFA, ACI, among other things. I even said "SDN" a couple of times. And thanks to the 80 or so people that braved snow (flurries) to attend! And those who drove 2-3 hours!

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Posted by on in Data Center

In this blog, I'd like to come at Practical SDN from a different point of view. Thanks to all those who slogged through the previous blogs in the series. I suspect those either had too much or too little information in them, depending on your point of view. Anyway, I've been mulling over my reactions to #SDN blogs, and especially some recent blogs about cross vendor abstraction. There have recently also been discussions about the idea that networking people need to learn to program, or do programming plus something. I had fun in a tweeting marathon one recent morning with @colinmcnamara and others. And Greg Ferro (@etherealmind) wrote a good blog about the topic.

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Posted by on in Data Center

I noticed that you may not initially be able to set the clock time and date on Nexus 5Ks. For example:

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Posted by on in Data Center

I will be presenting in the CMUG (Cisco Mid-Atlantic User Group) session on Tuesday February 2/25/2014. The formal abstract and announcements are here. The location is: Loyola University Columbia Graduate Center (8890 McGaw Rd, Columbia, Maryland 21045). There will be a continental breakfast served starting at 0800, with the presentation to start at 0900. (Google maps for this on my PC is a bit odd, showing McGaw not connecting to Dobbin Road. It's fine and correct on my iPhone.)

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The third in the series on SDN monitoring (Monitoring a Software Defined Network, Part 3) talks about the management system architecture. What factors drive the placement of monitoring system components? What drives the overall architecture? Are there any really important factors that determine how an SDN monitoring system should be designed?

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Tagged in: network management SDN

Posted by on in Data Center

One of my colleagues asked me if I knew what he could use to test Cisco twinax cables - specifically the SFP-H10GB-CUxM passive cables, and the SFP-H10GB-ACUxM active cables.  These cables are identified in the industry as SFP+ direct-attach copper cables, and can be used to interconnect Nexus switches and other devices at 10GE. He has recently connected a bunch of them in his data center.

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I am doing a 3-hour workshop on SDN at Enterprise Connect 2014 in Orlando, Florida, March 19, 2014. The session is titled "Powering Enterprise Communications with Software-Defined Networks (SDNs)." There will be a tutorial on SDN, followed by examples of using SDNs in enterprise networks by three leading vendors, HP, Cisco, and NEC. Each company has quite a different perspective on SDN, so it should be an interesting and informative session.

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Tagged in: SDN

Monitoring an SDN is going to be an interesting proposition. I wrote about the first part of monitoring and management in Monitoring a Software Defined Network, Part 1. I talk about monitoring stuff that happens on the network (i.e. switch or data plane) side of an SDN. Many of the low-level errors that we monitor today in traditional networks are also important in an SDN.

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It's time to talk (briefly!) about how NSX, DFA, and ACI handle Security. This blog series has already covered ARP, L2 forwarding and L3 forwarding, complete with many technical details. I'm hoping this blog will be a bit shorter, making easier on me doing the writing and you the reader. I intend to focus on where there's something interesting to cover.

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Posted by on in Network Infrastructure

I've been writing up an internal NetCraftsmen QoS template for a Cisco 3850 switch. This blog relates some lab experiences with the 3850. I hope it provides some useful information for those grappling with 3850 QoS. The second half of the blog is some observations and personal philosophy about QoS. I have quite a few more such than are revealed below -- but, hey, I'm trying to write a relatively short blog for once!

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