Showing posts from 2012

Meraki and the The Cisco Cloud Networking Group

I think this is the most interesting part of the acquisition;

"Cisco’s strategy is to take Meraki’s cloud platform and business model and scale this within Cisco as our new Cloud Networking Group, led by Sanjit, John, and Hans." I wonder if any existing Cisco groups will be moved into the Cloud Networking Group.

Cisco Announces Intent to Acquire Meraki | November 18, 2012 at 5:34 pm PST
Cisco is dedicated to innovation as the path to growth as well as the key to sustaining our market leadership position. Our build, buy, partner strategy has always been driven by customer need and on capturing market transitions.

Today, we are excited to announce an important acquisition that addresses the rapidly occurring shift to cloud networking as a key part of Cisco’s overall strategy. San Francisco-based Meraki, a leader in cloud networking, offers customers on-premise networking solutions that are centrally managed from the cloud.

When compared to other opportunities, Mer…

Over 50 FREE VMware Instructional Videos Available at

Over 50 FREE VMware Instructional Videos Available at

VMware Education has released a new video site with over 50 of our free instructional videos, on products including: vSphere, vCloud Director, Site Recovery Manager (SRM), vFabric, and more. Now you can grow your IT skills with free training, expertise, and insights on VMware products, all in one convenient location.
Instructional Videos – freely accessible, these short technical videos allow VMware technical experts to provide tips and step-by-step instructions on product features, design best practices, configuring, deploying and running your virtual infrastructure.


Administering VMware Site Recovery Manager 5.0 - Book Review

I received a copy of Mike Laverick's "Administering VMware Site Recovery Manager 5.0". This is a terrific book as the first book from VMware Press. Mike's has been providing terrific guides, white papers, and videos for years on his website RTFM Education.

To some the organization and presentation of this book may seem unconventional. Chapter 1 describes Site Recovery Manager, DR technologies, and addresses misconceptions of VMware technologies often thought of as DR technologies. Chapters 2 - 6 individually explain how to configure Dell, EMC Celerra, EMC CLARiiON, HP StorageWorks, and NetApp storage for VMware. Chapters 7 - 16 then cover the configuration and operation of VMware SRM. Chapters 1 plus one of 2 -6 make this book worthwhile to anyone installing a VMware solution with a SAN.

With my background being long in the teeth with networking and a little green in virtualization, Chapter 1 was most significant to me. I have been trying to understand the architect…

Cisco Unity vs. Unity Connection - Installation and Recovery Times

For several years Cisco has offered two Unified Communications voice messaging products. Unity, built on Windows Server, Exchange (or Lotus Domino), and MS SQL, and Unity Connection built on Linux and Informix.

I just spent 12 hours restoring a Cisco Unity system and thought this would be a good time to discuss the installation and disaster recovery process. I will skip the configuration steps to integrate with the phone system, create voice mail users, etc.

Overview of the Cisco Unity Installation ProcessI have been building Cisco Unified Communications Systems (or VoIP systems for the ol'timers) since 2000. Regular Unity has always been a complicated and comprehensive installation. There are many steps including things like "click options 2,3 and 5", "before proceeding to the next step, install this patch on the Exchange server", "if the Partner Exchange server is version 20XX, install Engineering Special ES9".

There is really four installations; Win…

Radia Perlman Talk on TRILL and Spanning Tree

I found this YouTube Google Tech Talks presentation by Radia Perlman. She is often referred to as the "Mother of the Internet". She invented the spanning tree algorithm. She also invented concepts that made "link state routing" stable, scalable, and easy to manage. The protocol was adopted and renamed IS-IS. She is credited as creating the original concept of TRILL.

Her presentation is titled "Routing Without Tears; Bridging Without Danger". She discusses the creation of spanning tree, link state routing protocols and finally TRILL or Transparent Interconnection of Lots of Links. Those of of working with network infrastructure and Cloud Computing can really appreciate everything she has done.

The Best Solution is the Simplest Solution

As a consultant I am sometimes brought into, shall we say, challenging situations. Some situations are primarily politically challenging, others are technologically challenging.

Today I have met a technically challenging situation. I am working on a network that is not, on the surface, much different than many others. In this case, the problem is someone has, from the technology or geek standpoint, created a very complex network. We have OSPF, EIGRP, and static routes. OSPF and EIGRP redistributing each other, and each redistributing static routes, plus back door links.

Now this environment had some challenging networking issues to deal with. However I am thinking of my favorite philosophical law called  Ockham's Razor. "It is a principle urging one to select among competing hypotheses that which makes the fewest assumptions and thereby offers the simplest explanation of the effect."

Sometimes the best solution is the simplest.

Cisco Configuration Tip - 3rd Party SFP Modules

It is possible to use non-Cisco SPF modules in a Cisco Catalyst switch. By default this is forbidden not allowed, but a top secret hidden command can make this happen.

switch(config)#service unsupported-transceiver
switch(config)#no errdisable detect cause gbic-invalid

In the SFP modules EEPROM, a Serial Number, Vendor Name & ID, Security code and a CRC. The switch reads these values and if they are not "Cisco" values reports an error such as:

%PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found in Gi1/0/1
%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port 65538 has bad crc

The official position from Cisco is:
Q. Do the Cisco Catalyst 3750 Series Switches interoperate with SFPs from other vendors?
A. Yes, starting from 12.2(25)SE release, the user has the option via CLI to turn on the support for 3rd party SFPs. However, the Cisco TAC will not support such 3rd party SFPs. In the event of any link error involving such 3rd party SFPs the customer will have to …

Cisco Configuration Tip - Command Macro To Change IP Address

Remotely changing an IP address on a Cisco router or switch, or moving an IP from one interface to another can be a challenge.

Cisco allows you to use macros although I have not really worked with them. rekrowteN has a great blog post about using macros to move an IP address from one VLAN interface to another.

In a previous Configuration Tip I discussed using the reload in/at commands to prevent getting locked out of a router or switch.

In this scenario we need to move the IP Address assigned to interface VLAN 1 to VLAN 10.
For this tip start by entering reload in 15.

Next we create the macro
conf t
macro name mgmtchange
interface vlan 1
no ip address
interface vlan 10
ip address
no shutdown
The "@" signifys  at the end of the macro. To apply the macro enter:
conf t
macro global apply mgmtchange
Once the change is made and you can reconnect don't forget reload cancel.

Configuring Command Macros

Have you used macro's? What Macro scrip…

Cisco Configuration Tip - Protect Your Tail

I have long been a fan of the Cisco "reload in/at" commands. These have saved my tail a number of times. This enables a brave network engineer to schedule a device reload for either a specific amount of time from now, 15 minutes, or just a specific time such as 11:00pm.
Protect Your Tail
This has saved my tail a few times when working on a remote device. When changing ACLs or firewall rules there is always the potential of getting locked out. It has also saved me when debug messages flooded a device and I could not get the telnet/ssh session to respond.

Bonus Tip: When I have to debug a router or a switch I open a second telnet/ssh window. The primary window is set to terminal monitor so I can see the messages. In the second window I type in "undebug all" but don't press enter. If the debug messages get out of hand in the primary window, I switch to the second window and hit enter. Before making configuration changes, do the following:
copy run start
terminal monit…

Configuration Tricks - Catalyst 4900M with CVR-X2-SFP and 1Gb SFP

The Cisco Catalyst 4900M is a high performance, low latency, layer-3 switch suitable for Top of Rack 10Gb link aggregation or small data centers server connectivity. eWeek testing validated 320 Gbps throughput, or 16 10G ports running at full line speed with latency of ~2.6 microseconds.

The 4900M chassis includes 8 fixed wire-speed X2 ports. Two half-card module slots can be added for additional ports. Supported modules available are:
WS-X4920-GB-RJ45 - 20 port 10/100/1000 RJ45WS-X4904-10GE - 4 port wire speed 10GE (X2)WS-X4908-10GE - 8 PORT 2:1 over subscription 10GE (X2)WS-X4908-10G-RJ45 -  8 PORT 2:1 over subscription 10GbaseTI recently had a situation were we deployed a Catalyst 4900M with the WS-X4920-GB-RJ45 and WS-X4908-10GE modules. The switch needed to connect a 1GB metro Ethernet circuit. No problem, with the 20 port 10/100/1000 module we had it covered...So I thought.

The service provider handed off 1GB multi-mode fiber.

How Do I Connect 1GB Multi-Mode Fiber To This Thing?