CCNP DC – 642-997 DCUFI Exam, DnD

Hope this will help you to prepare for 642-997 DCUFI exam.


Q1. DC Design Layer Characteristics



Q2. Cisco Nexus Design Layer and Features



Q3. Cisco Nexus Product Family Features



Q4. FCoE Protocol and Fibre Channel features



Q5. VSAN and SAN Zoning


Good luck to your study everyone! 🙂



Notes on Cisco QoS: Clearing the fog – Part 2. Quality issues

Quality of Service

QOS = Method of giving priority to some specific traffic as moving over the network.

The basic aim of QoS is to have a consistent and predictable performance on your network.


1 qos intro

General characteristics of today’s Converged Network:

  • Small voice packet compete with bursty data packets, many different applications are using network as services
  • Critical traffic must get priority over less critical traffic, without QoS, default behavior is First In First Out (FIFO)
  • Voice and video traffics are time-sensitive
  • Outages are not acceptable


Converged Network Quality issues:

  • Lack of Bandwidth
  • Packet Loss
  • Delay
  • Jitter



2 Bandwidth Measure.png

  • Maximum available bandwidth is the slowest link on the traffic paths
  • On the same physical links (traffic paths), multiple flows compete for the same bandwidth, multiple applications sharing the same bandwidth
  • Lack of bandwidth causes performance degradation on network applications



Packet Loss

3 Tail Drop due to Queue Congestion

Packet loss due to Tail Drop: Queue only can so much packets and once it is full and more packets arrive at the tail end of the queue before the queue is emptied (due to link congestion etc.), the packets will be dropped, and this behavior is called ‘Tail Drop’. If the tail drop occurs to the time sensitive traffics such as voice and video, the effects are immediately felt by the users on the flow. If this happens to data traffic, it may interrupt file transfer and corrupt the file.




4 Types of Delay

  • Processing Delay – time taken by router to process packets from an input interface and put them into the output queue of output interface
  • Queuing Delay – time a packet resides in the output queue of a router
  • Serialization Delay – time taken to place bits on the wire
  • Propagation Delay – time taken for packets to cross links from one end to the other end




5 Jitter

  • Packets from a source will reach a destination with different delay times
  • Congestion on the network will cause jitter
  • Congestion can occur at a router interface/Service Provider network if the circuits are not properly provisioned


CCNA Data Center 640-911 DCICN – Note 18, IPv6 Introduction

This is my first blog in 2016, I have been on holiday mode as I have been on one the longest annual leave in my life. Hope you understand the family commitment when you and your kids are on summer holiday (here in Sydney, Dec/Jan/Feb is blazing summer).


IPv6, the history and does it really matter to you or anyone?

The simple answer is YES, then why? The single biggest driver behind the development and introduction of IPv6 is  a long prediction of lack of usable IPv4 IP addresses since the explosion of World Wide Web (www) in 1995. The www development goes back to 1991 and then the introduction of grandfather web browser, Mosaic was first introduced in 1993. By year 1995, one third of IPv4 addresses were consumed, by year 2000, half of all IPv4 addresses were use.

As reviewed in previous notes, IPv4 consists of 32 bit address structure and theoretically that should give us 2 to the power of 32 IP addresses, that is 4294967296 IP addresses or roughly, 4.3 billion IP addresses . But not all IP addresses are usable such as the reserved IP addresses for private network use as well as the Class E addresses reserved for development and testing purposes. In other words, only around 2.5 billion IP addresses are true usable addresses. If you just check out our world’s population today (, China = 1.407 billion and India = 1.2912 billion people,), just looking at top two countries’ population figures, you can feel the IPv4 address shortage on your skin. The trend is that the world’s network has been doubling in size every year for the past 15 years. (

With the advancement of new technologies comes the rapid deletion of available IPv4 IP addresses. Anything that’s related to mobile communications and entertainment as well as all other areas seems to be needing more and more IP addresses for everyday use. In the past, it was expected that all the IPv4 addresses would be depleted by 2011 but it is 2016 and we are still using IPv4 address without much thought, all thanks to the counter measures put into place to slow down the IPv4 IP address deletion. e.g.) The fine art of sub-netting, a practical use of DHCP and IP Natting.


 Quick note on history of IPv6:

1990 – IETF had predicted that all class B IPv4 IP addresses will be deleted by 1994
1991 Nov – IETF formed  ROAD (ROuting and ADress) Group in Santa Fe, US.
1995 – IPNG (IP Next Generation) Workgroup had written and submitted ‘RFC 1883’, this RFC has become the foundation of current IPv6.
1996 – 6Bone was introduced. 6Bone was a test-bed for IPv6 vulnerabilities connecting 57 countries across 1100 sites.
1999 – IPv6 Forum was launched to standardize the use of IPv6
2006 Jul 06 – 6Bone was decommissioned after 10 years of testing.
Current – Majority of IP products are manufactured with IPv6 capabilities and compatibility. IPv6 is slowly phasing out IPv4 around the world.



Quick note on 10 Advantages (Characteristics) of IPv6:
1. Larger IP address space than IPv4, 32 bits based IPv4 vs 128 bits based IPv6
2. Better end-to-end connectivity than IPv4
– peer-to-peer application connections such as games, video conferencing, file sharing and VoIP
– No need to use NAT as the shortage of addresses is thing of IPv4
3. Plug-n-Play feature of IPv6
– plug-and-play auto-configuration, e.g.) DHCPv6
4. Simplified Header structures leading to faster routing
5. Better security features
– use of IPSec (a built-in feature)
6. Improved QoS features
7. Improved Multicast and Anycast abilities
8. Better mobility features
9. Ease of administration over IPv4
10. IPv6 follows the key design principles of IPv4


In the next section, we will look at some characteristics of IPv6 and then in the final section of IPv6, I will demonstrate IPv6 in a simple lab. Happy blogging, reading and all the best with your learning and career in 2016.

SQL Lessions – 1. Download and install

About 2 years ago, I bought a SAM’s quickie learning series book on SQL but it was sitting in the bookshelf and never been used. I am going to FORCE myself to learn and understand a little about SQL, and hopefully, on the way, I can share the documentation and learning with others. SQL, Sequel, Structured Query Language, however you call it, as an Engineer, you will come across it and hear about it as the current trend is all on Cloud and Big Data technologies. Behind the Cloud technology is powerful data centers with super computers and network devices. In the same Data Center, the Big Data reside on these servers, they live on virtual servers and SAN. The applications using these Big Data technologies are SQL apps [Oracle, IBM Infomix, MS-SQL, MySQL]. So, it is inevitable that you should make an effort to understand a little bout SQL I will be using free software called MySQL installed on Windows 7 laptop. Please find the installation steps to begin our journey into SQL: Step 1: Go to and download the latest mysql version mysql1 mysql2 Step 2: Extract the zip file to C:\ mysql3 mysql4 Step 3: Once the files are fully extracted, rename the folder to ‘mysql’ mysql5 mysql6 Step 4: Go to Computer > Properties > Advanced system settings > Environment Variables > Under System variables, find ‘Path’, then Edit > add “;C:\mysql\bin” mysql8 mysql9 mysql10 mysql11 mysql12 Step 5: Open command line as administrator mysql13 Step 6: Change the folder to mysql/bin folder and run ‘mysqld –install’ command to complete the installation mysql14 Step 7: Open services or services.msc as administrator mysql15 Step 8: Locate ‘MySQL’ service and start the service mysql16 Step 9: Now open Command Line and go down to C:\mysql\bin and start mysql mysql17 Now you are ready for your lesson 2. Let’s take one lesson at a time and slowly. Do you guys like potato chips? I DO! and I find slow cooked chips taste better. 🙂


CCNA Data Center 640-916 DCICT – Note 23. UCS Management

UCS Management Options

The UCS Manager (UCSM)


Where does the interface live in?

– Lives in Fabric Interconnect (FI)

– Active and Subordinate Interface

Admin interacts with 1 of the 3 interfaces:

Uses, XML API for the interface no matter which interface is used.

  1. GUI – The main tool
  2. CLI – Of course
  3. 3rd Party Tools – other vendors can write code to interact with UCS boxes

Is there other management protocols? YES

  1. SNMP – Simple Network Management Protocol
  2. KVM over IP
  3. IPMI – Intelligent Platform Management Interface
  4. SMASH CLP – Server hardware Command Protocol
  5. CIM – Common information model
  6. XML –
  7. SoL – Serial over LAN
  8. Call Home – notify Cisco TAC for you in automated fashion

UCS is designed from ground up to be manageable from Human interface.

“Discovery” = As you add equipment, UCS constantly discovers inside UCS and monitor using XML information format. Either automated or manually triggered discovery.

“FSM” (Finite State Machine) = Monitor particular complex processes on FSM.  For very involved process problems.

Complex processes for FSM: Server Discovery, Service Profiles, Firmware Downloads, Upgrading of UCS components system, Backup and Import are subject to FSM validation.\


Exam Question: Which would not be considered a primary method for management of a B-Series blade in the UCS? (Choose 2)

  1. IPMI
  4. XML-API
  5. SNMP

Answers: A & E

Explanation: These choices are secondary network management vehicle to manage UCS system.

CCNA Data Center 640-916 DCICT – Note 24. Pools, Policies and Profiles

Cisco Unified Computing System Manager – UCSPE

UCS Manager Pools, Policies and Profiles – used by DC Admins to deploy visualized servers in real advanced environment.


– Hardware abstraction

UCS Blade B series servers provide:

– Stateless Computing = MAC and WWN are burnt in traditionally but in HW abstraction, this is visualized and unlocks the tie to hardware.

– Controlled by Administrators.

– Service Profiles – Unique to each server blade. Provides Identity, MAC, WWN and Policy, QoS etc.


– Pools

* Create a pool to be used while creating a new virtual machines:

On CUCPE > Servers > Pools > Root


– Pools > root > Server Pools > UUID Suffix Pools > Pool default


– Very powerful tool for virtual machine deployments

– Ability to automate through the pools. E.g. Servers, LAN (e.g. MAC addresses), SAN, VM, etc.


– Profiles

On Cisco Unified Computing System Manager:


on CUCPE > Servers > Service Profile > [Right click to create profiles]

  1. Identify Service Profile (UUID)
  2. Networking
  3. Storage
  4. Zoning
  5. vNIC/vHBA Placement
  6. Server Boot Order
  7. Maintenance Policy
  8. Server Assignment
  9. Operations Policies


– Policies

On Cisco Unified Computing System Manager:


on CUCPE > Servers > Policies > root > [different policies for various settings]

– How particular servers deployed will react

– Dictate server behavior within UCS server


– Templates

On Cisco Unified Computing System Manager:


on CUCPE > Servers > Service Profile Templates

*Creates a standard settings so copy and tweak servers easily.

CCNA Data Center 640-916 DCICT – Note 6, Exploring vPCs and show commands




vPC related useful show commands:

‘show vpc brief’ = shows vpc domain ID, peer adjacency, Peer alive, Configuration consistency status, vPC role, Number of vPC configured, vPC Peer-link status and allowed vlans.

‘show vpc peer-keepalive’ = details of the vpc keep-alive status, keep-alive parameters

‘show vpc role’ = check vPC role status, check role-priority value

‘show vpc consistency-parameters interface port-channel XX’ = shows important local values compared to your peer’s values, checks non-consistent values