After a year of on and off again studying of Cisco’s CCNA I can finally say that I am CCNA certified. It’s not an easy exam to pass. The CCNA exam is a lot harder compared to the Network+, which was my last certification. The format between the Comptia and Cisco exams are definitely different. The CCNA requires a lot more studying and with experience it may be a lot easier.

Hands on experience is a plus with the CCNA. Physical routers and switches are a big advantage for doing labs while doing theory. If purchasing hardware is out of the question there is Packet Tracer which you receive complimentary if you’re part of the Cisco Academy. I’ve played around with Packet Tracer and it will help you get a lot closer to passing the CCNA exam.

Another application very useful and very popular is GNS3. With GNS3 you have the flexibility of creating various network topologies. The downside to using GNS3 is that you need to supply your own IOS images which can be found on Cisco.com.

After thinking about my CCNA journey I felt that I did not do enough lab work. I recommend getting as much lab work as possible before taking the CCNA exam. It will help you memorize the commands needed to answer exam questions. If you have commands burned into your brain then you will not waste any time guessing and using the “?”.

For a long time I wasn’t studying properly. I would just read without taking any notes or review. Now what I do is write down any important topics worth memorizing for the test and for the real world. Afterwards I review my notes and make sure I memorize commands and other important items pertaining to each technology.

Along with reading Wendell Odom’s ICND1 and ICND2 books I watched videos from Trainsignal. Computer based training alongside good theory and labs will help you pass the CCNA exam.

Related posts:

1. How To Study For the CCNA Exam
2. I Successfully Passed the Cisco ICND1 Exam!
3. CCNA ICND1 Test is Scheduled!

Virtual LAN Concepts

All LAN devices are in the same broadcast domain.

Common reasons to use vlans:

• flexible designs by departments or groups instead of by location
• reduce overhead to each host in a vlan by segmenting
• reduce workload of STP by limiting a vlan to a single access switch
• enforce better security
• separate traffic sent from an IP phone

Trunking with ISL and 802.1Q

VLAN trunking is used on segments to share VLAN information between multiple connected switches.

Two types of trunking protocols:

• ISL (Inter-Switch Link)
• 802.1Q

ISL

Inter-switch link. Cisco proprietary
Only used between Cisco switches
Encapsulates original ethernet frame in an ISL header and trailer
Supports normal & extended vlan range
Allows multiple spanning trees
Doesnt use native vlan

802.1Q

IEEE Standard
Inserts extra 4-byte VLAN header into original Ethernet frame
Supports normal & extended vlan range
Allows multiple spanning trees
Uses native vlan

VLAN Trunking Protocol (VTP)

Cisco proprietary way of sharing vlan information with other cisco switches.

There are three VTP modes:

• Server
• Client
• Transparent

To disable VTP put switch in transparent mode.

VTP Server has the capabilities of creating new vlans & the vtp server distributes that information over ISL or 802.1Q trunks.

Updates are based on revision numbers and are incremented by 1.

VTP clients simply receive and forward VTP messages and update the local vlan.dat to a newer revision, if available.

VTP servers & clients send VTP messages every 5 minutes

VTP Transparent switches don’t update their vlan configuration but they do forward along VTP messages to other switches (done with VTP version 2)

Three requirements for VTP to work between two switches:

1. Link between switches must be operating as a trunk, either ISL or 802.1Q
2. Both switches must have matching, case-sensitive, VTP domain name
3. Switches VTP, case-sensitive, passwords must match

VLAN information is stored in the vlan.dat database.
To delete the contents use command:

delete flash:vlan.dat

VTP Pruning

Allows VTP to dynamically determine which switches don’t need frames from certain vlans.

VTP prunes vlans from the appropriate trunks.

VTP pruning increases the available bandwidth in a network.

VLAN & VLAN Trunking Configuration & Verification

Configuring a VLAN Trunk

switchport trunk encapsulation {dot1q | isl | negotiate} an interface subcommand

Administrative mode refers to the configuration setting on an interface which means “what is configured”

Operational mode refers to what is currently happening on the switch.

Trunking Administrative Modes

• access – prevents trunking and puts interface as always nontrunk
• trunk – always uses trunking
• dynamic desirable – initiates negotiation of deciding to start using trunking and defines the encapsulation
• dynamic auto – waits for the negotiation of trunking

Reasons why a switch could prevent a particular vlan from crossing a trunk:

• vlan was removed from the trunk’s allowed vlan list
• the vlan doesn’t exist or it is inactive
• the vlan was pruned
• STP placed the trunk interface into a state other than forwarding

VTP Configuration & Verification

Configuring VTP

vtp mode {server | client}
vtp domain domain-name
vtp password password (optional)
vtp pruning (optional)
vtp version 2 (optional)

Where VTP Clients and Servers Store VLAN Related Configuration

Troubleshooting VTP

Step 1: Confirm switch names, tpology and vtp modes

Step 2: Use show vlan command on two sets of neighboring switches and see if the vlan database differs

Step 3: On differing databases, verify the following:

Related posts:

1. How To Configure a Router-on-a-Stick
2. 5 Easy Steps to Securing Your Cisco Switch or Router
3. User VLAN Do Not Acquire DHCP Address

After many days of hard work, studying, memorizing and testing I have successfully passed the Cisco ICND1 portion of the CCNA certification. Over the weekend I felt that I was 100% ready so I decided to bump the test up one day.

I did a lot of reading in order to pass the ICND1 which can be seen from my notes in my CCNA portion of the blog. The read Wendell Odom’s ICND1 book over and over until I memorized each key topic. Memorizing the information is the foundation for the CCNA certification. Go over each “key topic” and remember them as Wendell Odom points out.

Some of the other study materials I used to pass the ICND1 are

• Train Signal CCNA
• Boson Labs and Practice Exam
• Routersim
• CCNA Flash Cards

These are the same study materials I list in my “How to Study for the CCNA Exam“ blog post.

The most important thing to know is to download the ICND1 and ICND2 exam objectives. As long as you use those certification objectives as a guideline you will not have a problem passing the CCNA and obtaining a certificate. Don’t rush to learn everything and study at a comfortable pace.

I am immediately proceeding to study for the ICND2 exam and aim to be CCNA certified in November 2009. You can see my own study schedule as an example of how I learn the CCNA material and pass the exam at a fast and efficient rate.

Related posts:

1. CCNA ICND1 Test is Scheduled!
2. How To Study For the CCNA Exam
3. Passing the CCNA Exam

The next steps toward my Cisco CCNA certification is nearing! I’ve decided to take the two test route for two reasons:

• Easier to study
• Less Pressure

I didn’t want to pack so much information to study for in one test and I feel that doing ICND1 and then ICND2 will be very easy for me. Also, I am quite slow with the subnetting (even after numerous practice sessions) so the time allotted for the ICND1 and ICND2 exam will be perfect for me.

For the test, I purchased my voucher from Get Certify 4 Less, where the vouchers go on sale for up to 50% off!

The ICND1 and ICND2 Cisco exams are usually $125 for each test. I got my ICND1 test for just $85! The key point about these vouchers are that they expire in about 2 weeks. So when you make your purchase you should be 100% ready to take the test! You can definitely purchase regular vouchers too if you don’t want to feel pressured into studying for only 2 weeks but I highly suggest buying your voucher so you can set a definite date as to when you will take your test.

The vouchers for the Cisco CCNA exams that Get Certify 4 Less sells are for Pearson Vue test sites just so you know.

For my study and review process I am taking the Boson practice exam to see where I am at and then studying on the parts where I scored the lowest. I am also using a CCNA flash cards book I purchased at Barnes and Noble which is looking to be a huge resource for me. Not only do they go over key topics in flash card mode, there is a review section in the back for both the ICND1 and ICND2. I haven’t been using my GNS3 as much because of how the program interprets a switch through a router. The commands are a little different in that sense so I don’t want to confuse myself for the test.

Be sure to check in regularly at Get Certify 4 Less to see regular deals on CCNA exam vouchers.

Tune in next week for my test results

Related posts:

1. I Successfully Passed the Cisco ICND1 Exam!
2. How To Study For the CCNA Exam
3. Passing the CCNA Exam

IP addressing is the most important topic of the CCNA. You must know IP addressing inside and out in order to build, modify and troubleshoot a network. The CCNA will test your knowledge in this topic with lots of diagrams. Another core topic to know for the CCNA is routing, of course. This is a network certification which is based around routing packets, over WANs.

Fundamentals

OSI Layer 3 – defines routing and logical addressing.

OSI Network Layer defines: Routing, Logical addressing, Routing protocol, Other utilities such as DNS, DHCP and ARP.

OSI Layer 3 major protocol – IP, connectionless network layer protocol

IP – to route data (packets) from source host to destination host

IP will try to deliver packet but is discarded if cannot be delivered w/ no error recovery.

Routing

Routing – end-to-end logic of forwarding data

Routers discard data-link headers and trailers and extract IP packet.

Routers build routing tables with the use of a routing protocol.

Routing protocols learn about locations of the network layer groups in a network and advertise the groups’ locations.

A routing protocol learns routes and puts those in a routing table. RIP is a routing protocol.

Routing protocol defines the type of packet forwarded, or routed, for example IP is a routed protocol.

Rules for IP addresses:

• IP address in the same group cannot be separated by a router

• IP addresses separated by a router must be in different groups.

Learn how to use Cisco with Train Signal. Cisco is the leader in networking technology, touching every part of the enterprise. Click Here!

Concepts to memorize:

• When a host sends a packet it will send directly to the destination host if the IP address is on the same subnet as host.

• If destination IP address is not on the same subnet it will send packet to the default gateway.

When a router has to decide where to forward packets it will check data-link FCS field to ensure no errors occured, if errors occurred it will discard the frame. If no errors, it will discard old data-link header & trailer. It will then compare the IP packet’s destination IP address to the routing table, and find a route that matches the destination IP address. Helps identify outgoing interface of router and the next-hop router. It then encapsulates the IP packet inside a new data-link header and trailer, appropriate for outgoing interface (PPP or HDLC) and forwards the frame.

IP routing protocol goals

• dynamically learn & fill routing table w/ a route to all subnets in network

• place best route in routing table if more than one route to a subnet is available

• notice when routes in the table are no longer valid, and to remove them from the routing table

• if a route is removed from routing table & another route through another neighboring router is available, to add the route to the routing table

• to add new routes, or replace lost routes, w/ best currently available route as quickly as possible

• to prevent routing loops

Steps of a routing protocol

step 1: each router adds a route to its routing table for each subnet directly connected to the router.

step 2: each router tells its neighbors about all the routes in its routing table, including the directly connected routes and routes learned from other routers.

step 3: after learning a new route from a neighbor, the router adds a route to its routing table, with the next-hop router typically being the neighbor from which the route was learned.

Related posts:

1. Layers of the OSI Model
2. TCP/IP Model: Networking Basics
3. CCNA Notes on the Basics of WANs

As I progress in my CCNA studies I’ll be posting the notes I write up while reading or watching any CCNA training material. There’s a lot of fundamentals to understand and memorize for the CCNA exam but it also helps to actually know the material so you don’t have to look it up when you’re working on the job.

OSI physical layer defines the standards and protocols used to create the physical network and to send the bits across that network

Routers connect to a channel service unit/data service unit (CSU/DSU)
It is a four-wired cable from the telco that plugs into the CSU/DSU

Router cable and CSU/DSU are owned by customer
Wiring to the CO owned by telco
Demarc is one side where it is telco’s and one side that is customer’s responsibility. Typically, Demarc is where the telco physically terminates set of two twisted pairs inside customer building.

Cable between CSU/DSU and telco CO typically is RJ-48.

If router has built-in CSU/DSU, serial cable is not required. Typically just use RJ-48 cable.

To make point-to-point wan line work, devices need to synchronize their clocks to run at same speed (synchronization).

Device providing clocking, typically csu/dsu, is considered as the data communications equipment (dce).

Device recieving clocking, typically the router, referred to as data terminal equipment (dte).

Learn how to use Cisco with Train Signal. Cisco is the leader in networking technology, touching every part of the enterprise. Click Here!

HDLC – High-Level Data Link Control – determines if data passed the link w/o any errors; discards frame if errors occurred. Also identifies the type of packet inside the HDLC frame so receiving devices knows the packet type.

HDLC defines framing. Includes an Address field and Protocol Type field in trailer containing a frame check sequence (FCS) field.

HDLC has a 1-byte address field

HDLC performs error detection using FCS in HDLC trailer. If frame has error it discards frame with no error recovery performed by HDLC

PPP very similar to HDLC

Frame Relay networks are multiaccess. More than two devices can attach to the network.

Leased line, called access links, is installed between each router and nearby Frame Relay switch.

Frame Relay examines data frames from routers that are defined by it’s own data-link header and trailer.

Frame Relay header holds address field called DLCI (data-link connection identifier).

WAN switch forwards frame based on the DLCI

Telco equipment can forward one frame to one remote site and other frame to another remote site – which is considered to be a form of packet switching – means that service provider chooses where to send each data packet sent into provider’s network, switching one packet to one device and next packet to another.

Logical path of a frame between each router is called a Virtual Circuit.

Multiple sites can connect to VC

Related posts:

1. WAN Link Protocols
2. CCNA Notes – IP Addressing and Routing
3. Layers of the OSI Model

When there are multiple routing protocols on a router and metrics do not help, they use the default administrative distance per routing protocol. These are good numbers to memorize for the CCNA test. Cisco may test you on a simple question such as:

What is the administrative distance for RIPv1?

Routing Source	Administrative Distance
Connected Routes	0
Static Routes	1
EIGRP	90
IGRP	100
OSPF	110
IS-IS	115
RIP(V1 & V2)	120
Unknown	255

Related posts:

1. CCNA Notes – IP Addressing and Routing
2. CCNA Brain Farts: All Possible Valid Networks
3. CCNA ICND1 Test is Scheduled!

Studying for the CCNA is like studying for a test in high school. But if you’re doing self-study for the Cisco CCNA exam then it’s a bit tough, especially if you are rusty on your studying skills. Recently, I’ve changed how I am studying for the CCNA exam.

I used to just read through the book, chapter by chapter and casually answer the pre-chapter quizzes. As my practice exam shows, reading is not enough.

You really have to think about this and set a schedule for studying the CCNA to pass the exam.

The approach I am now taking to study for the CCNA exam:

• reading and taking notes

• review

• watching a computer based training video

• lab

• examination.

Reading & Taking Notes

A lot of what is on the CCNA exam is going to be memorization. To really nail the exam and pass quickly it’s good to know your show commands, cable lengths, etc. What I found best is while you’re reading you should write notes on what you think you should memorize and notes you think reflect the CCNA objectives. From your notes you can also create reference/cheat sheets that you can review when you’re on the go or in the lobby right before your test. There are many note-taking methods available but I find the cornell method very helpful.

Review

At the end of each chapter, if you’re reading Wendell Odom’s books, there are key topics you should go over and memory tables to memorize. Go through both of those after every chapter you finish reading. This is key to studying the CCNA exam and passing with a high score. You also gain real world knowledge.

Computer Based Training

I learn best by hearing and seeing. So it’s no surprise that I had to go out and purchase a CCNA training video. The best video for my studies and one that followed the book chapters well was the Cisco CCENT ICND1/ICND2 Trainsignal Videos. They provide a course outline on their site which fits perfectly alongside the Wendell Odom ICND book chapters. So after you read a chapter and review, move on to the lecture. Continue your notes from the book chapters and review your notes after the video training.

Lab

For the CCNA exam it is not absolutely crucial that you have a hands-on lab. It would be perfect to have one and it would certainly give you an advantage but most people can pass the exam by using virtual labs such as Routersim, Boson or GNS3. Whatever fits your budget is what I like to say. What I like about the Boson and Routersim virtual labs is that they contain lab documentation that cover all that you need to know for the CCNA exam.

Examination

As a networking specialist, we not only configure but we have to confirm. The same applies to the CCNA exam. After reading, watching, lab and reviewing we need to confirm that the knowledge we are taking in is being retained. In Wendell Odom’s CCENT books there are pre-chapter quizzes. The best way, in my opinion, is to read through all the chapters once. Then go back and take each chapter quiz. If you don’t score an 80% or higher then you should re-read that chapter. Once you score high on every chapter quiz you can move on to the Boson practice exam supplied on the cd in the book.

Take a simulated exam, 90 minutes and about 50 questions, testing your knowledge. For the areas you don’t score well on, study that area on study mode in the exam. Aim to achieve 100% that way you know you will pass the CCNA exam for sure.

Conclusion

Take the time to actually study the Cisco CCNA material and work to score a 100% on your practice exams. It’s best to study in an environment where there are no distractions such as the TV or the Internet. If you have computer networking experience then the exam will come easier to you but do not worry if you are starting from scratch. The goal is to get the knowledge so you can actually work on Cisco equipment in the real world.

Related posts:

1. Passing the CCNA Exam
2. I Successfully Passed the Cisco ICND1 Exam!
3. CCNA ICND1 Test is Scheduled!

The example I am showing you was built using the RouterSim Network Visualizer. I’m doing this as part of my CCNA studies to get me familiar with configuring a router and switch together and also making sure computers on different subnets can actually communicate with each other.

Here is the virtual hardware used in this virtual lab:

• Cisco 2811 Router
• Cisco 3560 Switch
• 2 x PC

Router on a Stick

The router on a stick is simply one router routing traffic between virtual local area networks (vlans). I’ll have the Cisco 3560 connecting to the Cisco 2811 Router. The 2 computers will connect to the 3560 switch but will be on 2 separate subnets or vlans.

Here’s what we’ll have to do this CCNA lab:

1. Configure two virtual interfaces on f0/1 for the 2811 router.
2. Configure f0/1 on the 3560 switch as a trunk interface to the 2811 router interface
3. Configure two ports on the 3560 switch on different vlans.

How to configure a router on a stick lab:

Open the console for the Cisco 2811 router. Type in the following commands (comments are made after the ! character:

Router>enable
Router#conf t
!! Change the hostname to R1
Router(config)#hostname R1

!! Create the virtual interfaces for f0/1
R1(config)#int f0/1
R1(config-if)#no shutdown
R1(config-if)#int f0/1.10
R1(config-subif)#ip address 10.10.10.1 255.255.255.0

!! I'm using the 10.0.0.0 network with a /24 subnet mask

R1(config-subif)#int f0/1.20
R1(config-subif)#ip address 10.10.20.1 255.255.255.0

!! Those IP's will be the gateway addresses for the PCs we'll configure later on

Now we move on to the 3560 switch:

Switch>enable
Switch#conf t
!! change the hostname to SW1
Switch(config)#hostname SW1

!! configure the trunk interface to R1
SW1(config)#int f0/1
SW1(config-if)#switchport mode trunk
SW1(config-if)#switchport trunk encapsulation dot1q

!! now configure the other ports, f0/2 & f0/3, on vlan 10 & 10 respectively
SW1(config-if)#int f0/2
SW1(config-if)#switchport mode access
SW1(config-if)#switchport access vlan 10
SW1(config-if)#int f0/3
SW1(config-if)#switchport mode access
SW1(config-if)#switchport access vlan 20
SW1(config-if)#end

Plug a PC into f0/2 of the switch and configure it with:

IP address: 10.10.10.10
Subnet Mask: 255.255.255.0
Gateway: 10.10.10.1

Plug a PC into f0/3 of the switch and configure it with:

IP address: 10.10.20.10
Subnet Mask: 255.255.255.0
Gateway: 10.10.20.1

Test connectivity between the two computers by issuing a ping to each other. If you get a reply then that means you’ve successfully configured a router on a stick.

Here is the full configuration for my R1:

R1>en
R1#show run
Building configuration...
Current configuration : 874 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!! CUT FOR BREVITY
!
interface FastEthernet0/0
  no ip address
  no ip directed-broadcast
  shutdown
!
interface FastEthernet0/1
  no ip address
  no ip directed-broadcast
!
interface FastEthernet0/1.10
  encapsulation dot1Q 10
  ip address 10.10.10.1 255.255.255.0
!
interface FastEthernet0/1.20
  encapsulation dot1Q 20
  ip address 10.10.20.1 255.255.255.0
!! CUT FOR BREVITY
end
R1#

And the configuration for SW1:

SW1>en
SW1#show run
Building configuration...
Current configuration : 868 bytes
!
version 12.2
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname SW1
!! CUT FOR BREVITY
!
interface FastEthernet0/1
  switchport mode trunk
  switchport trunk encapsulation dot1q
!
interface FastEthernet0/2
  switchport access vlan 10
  switchport mode access
!
interface FastEthernet0/3
  switchport access vlan 20
  switchport mode access
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface GigabitEthernet0/1
!
interface Vlan1
  no ip address
!! CUT FOR BREVITY
!
end
SW1#

What are your thoughts on the router on a stick? Do you have any input/questions/improvements?

Related posts:

1. Virtual LANs Notes
2. 5 Easy Steps to Securing Your Cisco Switch or Router
3. User VLAN Do Not Acquire DHCP Address

As I am currently studying for my CCNA, I find it very helpful to be able to practice creating networks in a non-destructive environment. Thus, GNS3 provides that solution. At first it was a little difficult installing it because you simply can’t type in

sudo apt-get install GNS3

That’s not even half of it. So here is how to install GNS3 and have it work efficiently for your CCNA studying needs.

1. First we will install Dynagen and Python-Qt4

sudo apt-get install dynagen python-qt4

2. Download GNS3 and extract in /opt

cd /opt
sudo wget http://downloads.sourceforge.net/project/gns-3/GNS3/0.6.1/GNS3-0.6.1-src.tar.bz2?use_mirror=softlayer
sudo tar -xjvf GNS3-0.6.1-src.tar.bz2 && rm GNS3-0.6.1-src.tar.bz2
sudo mv GNS3-0.6.1-src /opt/GNS3

3. Create the following directories:
These directories will be used by GNS3 – such as projects – where your working projects will be stored, cache, temp, IOS images, etc.

cd /opt/GNS3
mkdir Dynamips
mkdir IOS
mkdir Project
mkdir Cache
mkdir tmp
chmod o+rw -R ./Project
chmod o+rw -R ./tmp

4. Download binary of dynamips and make it executable

cd Dynamips
sudo wget http://www.ipflow.utc.fr/dynamips/dynamips-0.2.8-RC2-x86.bin
sudo chmod +x ./dynamips-0.2.8-RC2-x86.bin

You can create a desktop shortcut by right-clicking on the desktop and select “Create Launcher..”, Name it GNS3 and in the command section type in

python "/opt/GNS3/gns3"

Double click to open GNS3 and we will edit the default settings. If you don’t want to use desktop icons you can create a launcher from your programs menu by right clicking on the Main Menu, selecting Edit Menu. Select New Item on the right and you will be presented with the same window where you type in the above. From there you can move the launcher into any menu section of your choice.

5. Go to edit | preferences and in the ‘Terminal command:’ section type in:

gnome-terminal -t %d -e 'telnet %h %p' > /dev/null 2>&1 &

6. Under ‘Paths’ change the ‘Project directory:’ to

/opt/GNS3/Project

and the ‘IOS/PIX directory:’ to

/opt/GNS3/IOS

7. Click on Dynamips tab on the left

For the ‘Executable path:’ type in

/opt/GNS3/Dynamips/dynamips-0.2.8-RC2-x86.bin

8. Change the ‘Working directory:’ to

/opt/GNS3/tmp

Click on the Capture tab on the left

9. For the ‘Working directory for capture files:’ change it to

/opt/GNS3/Project

After you have done all that you will be able to Open and Save your GNS3 projects properly and have an efficient setup for GNS3. In order to use the devices in GNS3 you must obtain our own IOS images from Cisco.

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