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Upgrading ESXi Hypervisor to 5.1

Ahh the Christmas break. The perfect time for good food, enjoying the company of family and friends and of course…. IT projects at home! My project last year was to immerse myself in the source code for OpenBSD's snmp daemon so that I could integrate my patch-set for Net-SNMP directly into the native OpenBSD daemon. That was time well spent as I was able to integrate my code in the following weeks. This year I have maintenance to do in the home lab. It looks like 2013 is going to be a busy year as far as getting my hands on new stuff so I want the lab ready to rock.

First project: upgrade my VMware ESXi server from 4.1 to 5.1.

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Address Learning and the TRILL/FabricPath Control Plane

Do you ever find yourself in a conversation with someone where you attempt to explain a concept in detail and you realize that you don't know that concept at the level of detail that you thought you did? That happened to me recently. I thought I had a better handle on TRILL and FabricPath than I really did. Since I retain things far better when I write them down, I'm going to blog the differences between TRILL and FabricPath when it comes to address learning and what role the control plane plays in building the network topology

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Cisco UCS Manager 2.1 Highlights

Service Profile Renaming Yes, finally, you can rename service profiles. No more struggling to name your profiles perfectly the first time. When a profile is renamed, all the unique attributes including the MACs, WWNs, UUID, etc, are preserved. This can be done when the server is live and online without any impact. VM-FEX for Microsoft Hyper-V and KVM In addition to vSphere, VM-FEX (which I've written about here) is now available when using the Hyper-V or KVM hypervisors on UCS.

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Nexus 2000 Model Number Cheat Sheet

A colleague of mine pointed something out the other day: the numbers and letters that make up the Nexus 2000 (FEX) model actually have meaning! No, I haven't been living under a rock. I think it's pretty clear that with a model number like “2248TP-E” the “22” indicates this is the 2200 series FEX and the “48” indicates it's got 48 ports. But what about the letters that follow the numbers?

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AirPlay, VLANs, and an Open Source Solution

As I've written about in the past (here), Apple's AirPlay technology relies on Bonjour which is Apple's implementation of “zero config” networking. One of the things that Bonjour enables is the automatic discovery of services on the network. For example, an Apple TV might advertise itself as being able to receive AirPlay streams. An iPad that is looking for AirPlay receivers would use Bonjour to discover the Apple TV and present it to the user as an AirPlay destination. Both the Apple TV and iPad do all this without any user intervention or configuration (hence the “zero config” part).

That's fine and dandy but what my earlier article focused on was how Bonjour broke down in a network where what I'll call the “server” and the “client” are not in the same Layer 2 domain/VLAN. This is because the service discovery aspect of Bonjour relies on link-local scope multicast. These packets will not cross Layer 3 boundaries in the network.

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What the fex is a FEX anyways?

This is a quick, high level rundown of Cisco's various fabric extender technologies and where each fits into the data center.

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Doing Etherchannel Over 3, 5, 6, and 7 Link Bundles

As a follow-up to my previous article on Port Channels titled “4 Types of Port Channels and When They're Used” I wanted to talk a bit about the long-standing rule that says you should always create your Etherchannel (EC) bundles with a number of links that works out to a power of two (ie, 2,4 or 8 links). That rule is less applicable today than it used to be.

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4 Types of Port Channels and When They’re Used

The other day I was catching up on recorded content from Cisco Live! and I saw mention of yet another implementation of port channels (this time called Enhanced Virtual Port Channels). I thought it would make a good blog entry to describe the differences of each, where they are used, and what platforms each is supported on.

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Packets of Interest 2012-06-12 — OSPF Refresher

I was recently brushing up and refreshing my OSPF knowledge and I discovered some great resources that I wanted to document for my future use and also share with others. I found these resources great for explaining/detailing area types, packet types, and neighbor states. This first document hosted at packetlife.net is one of the best explanations of packet types I've ever seen due to the visual aids that the author, Jeremy Stretch, incorporated.

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Five Features of Brocade VCS

Virtual Cluster Switching (VCS) is Brocade's brand of datacenter ethernet switching. VCS allows for the creation of a network fabric that's capable of converging storage and data traffic via standards-based datacenter bridging. It also solves the “Spanning Tree Protocol (STP) problem” by implementing a standards-based TRILL data plane paired with their own control plane in the form of Fabric Shortest Path First (FSPF). This data + control plane enable the “routing” of MAC addresses through the fabric, negates the need for STP, enables the use of all cabled links, and prevents traffic loops. VCS is only (currently) available on the VDX line of switches from Brocade.

In this post I'm going to outline five aspects of VCS that I found particularly interesting or unique. This is a companion article to an earlier one titled Five Functional Facts about FabricPath where I broke down five features of Cisco's fabric technology.

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OpenBSD 5.1 SNMP MIBs

It's May and that means a new version of OpenBSD is out. My SNMP MIBs have been updated for 5.1 and are available for download on the OpenBSD SNMP MIBs page. THIS WILL BE ONE OF THE LAST RELEASES OF THE MIBS FOR NET-SNMP During the OpenBSD 5.1 development cycle, I committed the CARP MIB to the base OpenBSD snmpd. The kernel sensor MIB has been in the base snmpd for a few releases now.

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Who? What? When? Wired? Wireless? With Cisco ISE

Cisco's Identity Services Engine (ISE) is a powerful rule-based engine for enabling policy-based network access to users and devices. ISE allows policy enforcement around the Who?, What?, and When? of network access.

• Who is this user? A guest? An internal user? A member of the Finance department?
• What device is the user bringing onto the network? A corporate PC? A Mac? A mobile device?
• When are they connecting? Are they connecting to the secure network during regular business hours or at 02:00 in the morning?

These questions can all be answered easily within ISE and are all standard policy conditions that are relatively easy to implement. In the post below I'm going to focus on the How? — How is the user or device connecting to the network? Asked another way, the question is Wired? or Wireless?

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Five Functional Facts about FabricPath

FabricPath is Cisco's proprietary, TRILL-based technology for encapsulating Ethernet frames across a routed network. Its goal is to combine the best aspects of a Layer 2 network with the best aspects of a Layer 3 network.

• Layer 2 plug and play characteristics
• Layer 2 adjacency between devices
• Layer 3 routing and path selection
• Layer 3 scalability
• Layer 3 fast convergence
• Layer 3 Time To Live field to drop looping packets
• Layer 3 failure domain isolation

An article on FabricPath could go into a lot of detail and be many pages long but I'm going to concentrate on five facts that I found particularly interesting as I've learned more about FabricPath.

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Android vs iOS: Opinions From a Long-Time Android User

I don't really keep up to speed on consumer technology. For me, the enterprise IT space holds more challenge and interest. There is one piece of consumer tech though that has become fully ingrained in my life: the tablet. For that reason, I'm going to summarize my experience in using both Android and Apple based tablets.

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How Unix Made Me a Better Network Engineer

I've had two main areas of interest in my IT career. Professionally, I've been a network guy. Designing, building, and supporting IP networks is what pays my bills. On the other side, I'm a Unix geek. Building, tinkering, and hacking code on Unix systems and related open source software has always been fun and challenging for me. Recently I was reflecting on my career and realized that my Unix and open source experience has played a big role in my career as a network engineer. Here's some of the ways I believe network engineers can benefit from Unix experience.

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Packets of Interest (2012-03-29) — Bonjour

These are some articles/interviews that I came across this week that got me thinking about Apple's Bonjour in enterprise environments.

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Cisco UCS and SR-IOV

I read an excellent blog post by Scott Lowe (@scott_lowe) this week on Single Root I/O Virtualization (SR-IOV) titled “What is SR-IOV?". It's an older post but it did a great job of solidifying my understanding and filling in the knowledge gaps. One thing that stuck out was this bit: SR-IOV requires support in the BIOS as well as in the operating system instance or hypervisor that is running on the hardware.

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RANCID and the Octothorpe

RANCID (Really Awesome New Cisco confIg Differ) is a tool for automating the collection of hardware and configuration data from network devices. I recently upgraded an installation from version 2.3.1 to 2.3.8. And naturally, because I didn't have a ton of time to devote to this, stuff broke. It stopped pulling data from some switches. Not all switches, mind, that would be too easy to troubleshoot. Only some.

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Net-SNMP and snmpd Coexistence on OpenBSD

Although it would be awesome to ditch Net-SNMP altogether now that the base OpenBSD SNMP daemon has support for all of the OpenBSD-related MIBS (CARP, PF, kernel sensors), reality is that Net-SNMP still offers some features that are needed. OpenBSD doesn't have any SNMP tools (snmpwalk, snmpset, etc) so these are still required from Net-SNMP. There's also some unique features in the Net-SNMP daemon that are still useful if you want to do things like monitor BIND9 or Postfix statistics.

Here's how to run both at the same time and leverage snmpd for the OpenBSD-related MIBs and the Net-SNMP daemon for its ability to retrieve data from scripts and extend itself using loadable modules and smux sub-agents.

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Switching from Net-SNMP to snmpd for CARP, PF and Sensor Monitoring

Update: For help running both snmpds at the same time, see Net-SNMP and snmpd Coexistence on OpenBSD

Now that OPENBSD-CARP-MIB and OPENBSD-PF-MIB have been added to the base snmpd in OpenBSD (CARP-MIB will be in 5.1-release, PF-MIB in 5.2, and the SENSOR MIB has been there since 4.5), I wanted to document the differences between these MIBs and the corresponding implementation of the MIBs that I wrote for Net-SNMP.

Both implementations provide the same set of OIDs and allow the same data to be retrieved. Whatever you were querying via Net-SNMP is available via snmpd.

What has changed is the base OID where the CARP and PF MIBs are rooted at as well as the name of certain OIDs.