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Excerpt: I passed 640-916 – Introducing Cisco Data Center Technologies earlier this week. I was going to publish this post on they day of or after the pass, but unfortunately I was put out of commission by the winter bug that’s going around and did not get to give this post the attention it deserved. The first test in the CCNA Datacenter track, which is 640-911 – Introducing Cisco Data Center Networking, was a pretty straightforward test for someone with my background. This exam focused on network-specific topics, but obviously with an emphasis on data center. I want to briefly address a group…
CCNA Datacenter
December 7, 2012 by 7 Comments
Netapp CNA Link Redundancy with a Single Nexus Switch
February 22, 2012 by Leave a Comment
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Excerpt: I ran into a configuration recently where I had a Netapp storage array with the UTA cards installed, so there two CNA ports on each filer for a total of 4 ports. However, instead of a dual-switch design, there was only a single Nexus 5000, and therefore, no vPC configuration. I needed to achieve some level of redundancy on an interface level, but ran into some problems which I’ll discuss. My topology looks like this: As you can see, there’s only one Nexus 5K, shown at the bottom. The two Netapp FAS3240 filers are connected via each Converged Network Adapter to a…
NX-OS Virtual PortChannels and Best Practices
February 8, 2012 by Leave a Comment
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Excerpt: Port-Channels, are a way of aggregating physical links together so that you can load balance traffic over each link to increase bandwidth, and create more redundancy. You might commonly see this configured between two switches, as shown below: Each link works together to form a logical, loop-free interface. These are relatively commonplace, and in this scenario highly useful because it prohibits spanning tree from blocking one of these ports, allowing the switch to utilize each link. But what if, instead of one Catalyst 6500, you had two? My previous post on VSS covered this in some detail. You are able to…
Port Monitoring/Mirroring on NX-OS: SPAN Profiles
January 25, 2012 by Leave a Comment
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Excerpt: Port mirroring is a very valuable troubleshooting tool. Cisco calls this SPAN, and it’s pretty easy to do. Cisco’s NX-OS platform does it a little differently than traditional IOS, so I wanted to briefly post a walkthrough. First, you have to set up the monitor session and configure source and destination interfaces: switch(config)# monitor session 1 switch(config-monitor)# source int port-channel 2 both switch(config-monitor)# source int port-channel 3 both switch(config-monitor)# destination interface ethernet 1/7 switch(config-monitor)# no shut switch(config-monitor)# Notice that I configured both downstream port-channels to be my source interfaces, and that I used the “both” keyword. This means that any traffic going over either port channel, in either…
KIClet: NX-OS Default Switchport State
January 19, 2012 by Leave a Comment
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Excerpt: Cisco switches (and the vast majority of other vendors) ship their switches with all ports in the enabled state. This allows someone with no networking background to plug stuff in, the switch starts learning MAC addresses, and everything works just fine. Sometimes it’s necessary from a security perspective to change this default behavior, so the network engineer is forced to “no shut” every port he or she wishes to use. In NX-OS this is a particularly interesting subject because it also is a security best practice to do this, not only for your Ethernet ports but also for Fibre Channel. The command…
