Monday, June 27, 2016

CCNA Data Center - opening remarks

I am about to complete my CCNA Data Center certification.  I have a CCNA Route & Switch due to expire in August, and with the change in my career focus to data center technologies, I felt it was more appropriate to continue this certification path in the data center instead of route/switch.

I'm beginning with the DCICN 640-911, "Introducing Cisco Data Center Networking" exam.  it covers many of the same topics as the CCNA R/S so I'm figuring I'll have a leg up.

So I purchased the Cisco certification guide and will begin there.

The Cisco guide begins with Networking fundamentals, including the OSI model, ethernet LANs, WAN and IPv4 addressing and routing.  It also goes into the fundamentals of TCP/IP transport and applications.

While I have to admit I don't use it every day, I do recall that the OSI model consists of:


  1. Physical Layer - the actual wiring and connectors
  2. Data Link Layer - physical addressing, error detection (CRC), Protocols include PPP, Frame Relay, HDLC
  3. Network Layer - logical addressing network devices, IP addresses, protocols include IP, IPX, RIP
  4. Transport Layer - end-to end communication and defines buffering, window size and flow control, error correction.  Protocols include UDP, TCP, SPX
  5. Session Layer - Establish, maintain and tear down sessions. Protocols include SQL, RPC, NFS
  6. Presentation Layer - Compression, encryption and decryption happen at L6.  Here protocols include ASCII, JPEG, GIF
  7. Application Layer - makes data available to software, protocols include FTP, telnet, HTTP(S), SMTP
Where TCP/IP combines some of these into:

  1. Link - OSI L1-L2
  2. Internet - OSI L3
  3. Transport - OSI L4
  4. Application - OSI L5-L7
As data moves from one layer to the next, it encapsulates the data it receives from the previous layer, adds some info to the header and passes it to the next layer.  The terminology for the encapsulated data at each layer is:

  1. L1 - bits
  2. L2 - frame
  3. L3 - packet
  4. L4 - segment
  5. L5-L7 data
Instead of bits-frames-packets-segments-data, the OSI model uses "Protocol Data Units" such as L7PDU, L6PDU, which consist of the data encapsulated in that particular layer's header and trailer.  Someone should have thought of that before everyone started with the commonly used terminology above...while it's more clear, let's face it...nobody uses that.

And a few other reminders for myself from chapter 1:

Adjacent-layer communication happens within the same computer between different layers, while same-layer communication occurs between different computers.  Adjacent-layer communication is when one layer requests or provides services to the layer above or below it.

The TCP/IP model in recent years shows the Link Layer at level 1 split into 2 layers, the Data Link and Physical layers.



Sending an F11 to ESXi from a Macbook Pro when using RDP to a Windows system for installation

Many more irritating moments spent wishing I had written this down somewhere.

I work remotely much of the time.  I'm currently reinstalling ESXi on a number of hosts and using a workstation located on the LAN of my office to hold the install ISO.  I'm accessing it via RDP from a Mac connected by VPN.  I have configured my Mac to use F-keys in a more traditional manner like I recorded in this post, but for some reason the F11 would show the desktop instead of actually instructing the ESXi installation to continue.

The secret key sequence is:

Command+F11

I don't know what it is about the Mac that makes it behave like this, but I'm tired of wasting time searching for this answer.  I hope I remember it now...

Friday, April 8, 2016

Avamar Commands

Avamar MCCLI commands I use regularly:

View all clients (pipe to grep for selective search):
admin@AVAMAR001:~/>: mccli client show --recursive=true

Retire a client:
admin@AVAMAR001:~/>: mccli client retire --name=</path/to/client>

Thursday, April 7, 2016

Naviseccli commands

A handy reference of naviseccli commands I use:

Get stats on a particular LUN:
C:\>naviseccli -h <SP> lun -list -l 56 -perfData
C:\>naviseccli -h 1.1.1.1 lun -list -l 56 -perfData

Get stats on all LUNs
C:\>naviseccli -h <SP> lun -list -perfData

Proactive disk copy to hotspare:
C:\>naviseccli -h <SP> copytohotspare <disk-to-replace> -initiate

Check status of disk with percentage rebuilt:
C:\naviseccli -h <SP> getDisk <disk-being-replaced> -stat -rb

Friday, February 12, 2016

A List for 2016

I have a few objectives this year and I've decided that I'll leverage the accountability of the Internet to keep me honest and on track.  I tend to be more purposeful when I write them out, and this helps me stay reminded of the long-term goals for the year in the midst of the daily fires and tasks.

So, without further ado, here is my list of career objectives for 2016:


  1. Build an effective monitoring process for our storage and virtualization platforms.  Over the past few years the company I have worked for has grown substantially, both organically and through acquisition.  This makes for a very dynamic storage infrastructure, requiring me to be able to report quickly and efficiently on where we're at today, where we've been based on landmark events, and what is a reasonable projection.  
  2. Expand knowledge and understanding of public cloud services and how they may integrate to serve our company's infrastructure.  While I haven't fully bought into migrating our data center into "the cloud," I'm afraid the writing is on the wall as far as the use of public/private cloud infrastructure goes.    There are several players involved, and my company is partnered with several.  To ignore this technology would be to ignore the future, and I've got a lot of "future" left in my career.  It will be better to know and understand well enough to make informed decisions where this technology is a good fit and if not, be able to answer with authority to state as such.
  3. Expand my understanding of OpenStack, SDN and related projects for data center orchestration.  Determine if there is a good fit in the mid-size enterprise for this technology.
  4. Expand my knowledge and use of Python as a means of automating processes in the data center.  This dove-tails into the above objective, as well.
  5. Renew my CCNA Route/Switch via CCNA Data Center.  My life seems to be going down the path of Data Center Engineering more than routing and switching.  I'll go this direction and use the CCNA/DC to renew my CCNA/RS.
I have several other objectives, but these are the over-arching goals.  I've decided not to include project-based goals I've already defined, such as upgrade our EMC VNX storage or add compute.  These are much more tactical objectives and I view them as daily work, not so much as objectives to increase my knowledge and expand my understanding.

I'll be posting my study notes again as I start down the CCNA Data Center learning track, and am also planning a trip to EMC World 2016 this year.  It's going to be fun and exciting...

Tuesday, December 1, 2015

Sending that pesky F11 to ESXi through a Mac

OK, the alternative method I've just discovered is to go to the keyboard settings under System Preferences and check the box that says:

Use all F1, F2, etc. keys as standard function keys.

This worked today.  We'll see what happens tomorrow.

Monday, September 28, 2015

Sending F11 to ESXi through UCS KVM on Mac

I just need a place to put this so I remember.  I switched to using a Macbook Pro - which I love.  But there are some things that just require learning again...

Sending F11 to an ESXi host through a KVM requires:

Fn+Cmd+F11

Now I may remember...