CCIE Quest.

This is something very Basic, but have lots of applications to some scenarios, and it is in the CCNA topics, so i will review it here. Is good to note i will be going through things like static routing, static routing using exit interface, static routing using next hop, and using default static routes to get to other networks. Things like floating static routes, ill cover them on another post(when Dynamic routing is involved).

Ok first of all what is static routing??? well static routing could be called, the procces of manually mapping networks to the routing table( what a concept!! ). The point of this?? well pretty much obvious so the router can know how to get to other networks, it does not know how to get. If a friend tells you , come by! to my home, and you do not know , his address, your lost!, so that means you need to know exactly how to get to his/her house. It is pretty much the same with ROuters, if a router does not know how to get to a network, it will discard the packets destined to those networks he do not know.That said we can move on.

Scenario

3 Routers connected in a Hub and spoke fashion. Serial links between them, and 6 loopbacks in every location for Lans simulation.

Static Routing using Exit interface/next hop address.

R0(config)# ip route 192.168.200.0 255.255.255.252 s0/0

Ok this is pretty simple. the ip route command is the one used to create static mappings. the syntax is ip route <destination network> <destination network subnet mask> <exit interface/nexthop> so what we are basically doing, is instructing R0 to when it receives a packet destined to network 192.168.200.0/30(p2p link between R1-R2) forward it through interface serial 0/0(Which is the interface pointing to R1).

When the packet arrives R1, R1 recognizes the address as part of network 192.168.200.0/30 and forward it to the interface belonging to this network(in this case pings will be succeful, when packets are sourced from R0 Serial link, and destined to R1 Serial link….Good to note…).

Now lets say we need connectivity to the whole LAN on R1(10.2.0.0/24) from R0.

on R0

R0(config)# ip route 10.2.0.0 255.255.255.0 s0/0

R0(config)# ip route 10.2.1.0 255.255.255.0 s0/0

R0(config)# ip route 10.2.2.0 255.255.255.0 s0/0

R0(config)# ip route 10.2.3.0 255.255.255.0 s0/0

R0(config)# ip route 10.2.4.0 255.255.255.0 s0/0

R0(config)# ip route 10.2.5.0 255.255.255.0 s0/0

We specified R0 how to get to the whole Lan on R1. But there is a problem, if packet where to transit between them(with a source addres of any host of the lan), they will get to R1 but they will not return, given to the fact that R0 knows how to get to R1 , but R1 does not know how to get to R0. So we need to specified R1 how to get to the Whole lan of R0.

on R1

R1(config)# ip route 10.1.0.0 255.255.255.0 192.168.100.1

R1(config)# ip route 10.1.1.0 255.255.255.0 192.168.100.1

R1(config)# ip route 10.1.2.0 255.255.255.0 192.168.100.1

R1(config)# ip route 10.1.3.0 255.255.255.0 192.168.100.1

R1(config)# ip route 10.1.4.0 255.255.255.0 192.168.100.1

R1(config)# ip route 10.1.5.0 255.255.255.0 192.168.100.1

Ok we now have specified R1 how to get to Whole lan of R0, but here we used a different approach, we used the next hop address in spite of the exit interface. You may ask what is the difference??? Well is very straighforward , Static routes pointing exit interface have a administrative distance of 0, cause the IOS sees them as directly connected. and Next-hop pointing static routes, have a AD value of 1.

Now Host from any R0 lan, can reach host on any R1 Lan and vice-versa. Now what happens if i try to ping the host on R2 lan, well ping will fail cause neither of them knows how to reach each other lan.

Static Routing using Default route.

Well on R2, we can have static mapping for all the addresses of R0-R1 lans or we can create a default route. This is called stub network, when a router only have one interface to the outside, every non local traffic only have one way out. this is a stub network. and it is even more easy to configure

R2(config)# ip route 0.0.0.0 0.0.0.0 s0/0

Every traffic destined to a any network(0.0.0.0….non local aka not known), with any subnet mask(0.0.0.0), forward it trhough Serial 0/0 interface.That means that when any host on any of the R2 lans, generates packets to any of the other networks it will forward them trhough interface s0/0.

REMEMBER: You need to specify on R0-R1 how to get to R2 Networks or it would be meaningless, and pings will not be succesful when sourced from R2 Lans, and R0 cannont reach R2 if R1 does not either know hot to get to R2, so keep that in mind. this means R1 need to have mappings to R2 networks.

On R0

R0(config)# ip route 10.3.0.0 255.255.255.0 s0/0

R0(config)# ip route 10.3.1.0 255.255.255.0 s0/0

R0(config)# ip route 10.3.2.0 255.255.255.0 s0/0

R0(config)# ip route 10.3.3.0 255.255.255.0 s0/0

R0(config)# ip route 10.3.4.0 255.255.255.0 s0/0

R0(config)# ip route 10.3.5.0 255.255.255.0 s0/0

on R1

R1(config)# ip route 10.3.0.0 255.255.255.0 s0/1

R1(config)# ip route 10.3.1.0 255.255.255.0 s0/1

R1(config)# ip route 10.3.2.0 255.255.255.0 s0/1

R1(config)# ip route 10.3.3.0 255.255.255.0 s0/1

R1(config)# ip route 10.3.4.0 255.255.255.0 s0/1

R1(config)# ip route 10.3.5.0 255.255.255.0 s0/1

Here we are seen what we have been doing til now, the only thing that has changed is the exit interface on R1.

This will leave us with total connectivy between all routers. This can be a lot more simplify by considering that R0-R2 are stub routers, and summarization on R1. This would look like this

on R0

R0(config)# ip route 0.0.0.0 0.0.0.0 s0/0

on R2

R2(config)# ip route 0.0.0.0 0.0.0.0 s0/0

on R1

R1(config)# ip route 10.1.0.0 255.255.0.0 s0/0

R1(config)# ip route 10.3.0.0 255.255.0.0 s0/1

With this Configurations, there should be Full connectivity between all routers(You can use a script…that i put at the bottom of this post ).

It is a good pratice to have debug ip routing on, while you configure static routes, and any other routing protocol,so you can see, in real time how are routes added to the routing table and lots of cool stuf(sorry morris! ).

This post is not the best post on static routing, but it is pretty much a good reminder for me of this simple task, so i hope you benefit from it somehow, feel free to give some feedback, i have tested this configuration , but feel free to to post if there is some error, or any thing that needs to be reminded.

Links:

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094195.shtml

http://en.wikipedia.org/wiki/Stub_network

http://www.cisco.com/en/US/docs/ios/iproute/configuration/guide/irp_ip_prot_indep_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1056183

Script.

To use this script, issue the following commands

R0#tclsh

When you get this prompt “R0(tcl)#” copy the text below and hit enter.R0(tcl)#

foreach address {

192.168.100.1
192.168.100.2
192.168.200.1
192.168.200.2
10.1.0.1
10.1.1.1
10.1.2.1
10.1.3.1
10.1.4.1
10.1.5.1
10.2.0.1
10.2.1.1
10.2.2.1
10.2.3.1
10.2.4.1
10.2.5.1
10.3.0.1
10.3.1.1
10.3.2.1
10.3.3.1
10.3.4.1
10.3.5.1
} { ping $address }

Day 26

Chapter: Basic Switch Configuration and port security

CCNA 640-802 Exam Topics
-Perform,save,and verify initial switch configuration tasks, including remote acess management.
-Implement and verify, basic switch security(including port security, unassigned ports, trunk access, and so on.)

1)Q: How do i access a vlan interface configuration mode
A: With the command Switch(config)#interface vlan <vlan-number> ex, interface vlan 12

2)Q: How do i define the Vlan membership mode for a port
A: With the command Switch(config-if)#switchport mode acess

3)Q: How do i assign a port to a VLAN
A: Switch(config-if)#switchport access vlan 12

4)Q: How do i configure Duplex settings on an interface
A: Switch(config-if)# duplex auto|full|half

5)Q: How do i configure speed settings on an interface
A: Switch(config-if)# speed auto|full|half

6)Q: How do i set up an default gateway in a switch
A: Switch(config)#ip default-gateway 172.17.50.1

7)Q: How do i configure a HTTP server for authentication using the enable password( which is the default method of HTTP server user auth).
A: Switch(config)#ip http authentication enable

8)Q: How do i enable the HTTP server
A: Switch(config)# ip http server

9)Q: Which is the default VLAN for all ports
A: The default VLAN for all ports is VLAN 1.

10)Q: Which is the native VLAN by default
A: By default, the native VLAN assigned to 802.1Q trunks is also VLAN 1.

11)Q: Which command is used to configure multiple ports
A: Switch(config)# interface range f0/5 – 10

12)Q: Which are the five steps for configuring SSH
A: Change the VTY lines to usernames, with either locally configured usernames or an AAA server.
A: Configure the switch to accept both telnet and ssh connections with the transport input telnet ssh vty subcommand.
A: Add one or more usernames.
A: Configure a DNS domain name with the ip domain-name command. this is necessary only ig you want to use a domain name instead of an IP address.
A: Configure the switch to generate a matched public and private key pair, as well as a shared encryption key, using crypto key generate rsa command.

13)Q: What is the use of port security
A: You can use port security to restric interfaces, so that only the expected device can use it.

14)Q: Which are the steps to configure port security
A: 1) Configure the interface for access mode usin the switchport mode acess interface mode subcommand
A: 2) Enable port security using the switchport port-security interface subcommand
A: 3) Specify the maximun number of allowed MAC addresses associated with the interface using the switchport security maximun number interface subcommand
A: 4) Define the action to take when a frame is received from a MAC address other than the defined addresses using the switchport port-security violation {protect|restric|shutdown}
A: 5) Specify the MAC address(es) allowed to send frames into this interface using the switchport port-security mac-address <mac-addess> command. or the switchport port-security mac-address sticky interface subcommand for dynamic learning.

15)Q: Which commands are used to monitor port security
A: show port-security
A: show port-security interface

Day 27

Chapter : Network Segmentation and Switching Concepts

CCNA 640-802 Exam Topics
-Explain Network segmentation and basic traffic management concepts
-Explain basic switching concepts and the operation of Cisco switches.

1)Q: How does Switching logic works
A: Ethernet selectively forward individual frames from a receiving port to the port where the destination node is connected. During this instant, the switch creates a full bandwidth , logical point-to-point connection between the two nodes.

2)Q: How does switches create this logical connection
A: Switches create this logical connection based on the source and destination Media Access Control(MAC)addresses in the ethernet header.Specifically, the primary job of a LAN switch is to receive ethernet frames and then make a decision: either forward the frame or ignore the frame.

3)Q: How the switch accomplish this
A: 1) Decides when to forward a frame or when to filter(not forward) a frame, based on the destination MAC Address
A: 2) Learns MAC addresses by examining the source MAC address of each frame received by the bridge
A: 3) Creates a (LAYER 2), loop-free environment with other bridges by using Spanning Tree Protocol (STP).

4)Q: What is a collision domain
A: A collision domain is the set of LAN interfaces whose frames could collide with each other. All shared media environments, such as those created by using hubs, are collision domains.

5)Q: How does switches differ from hubs regarding collision domains
A: When one host is attached to a switch port, the switch creates a dedicated connection thereby eliminating the potential for a collision.Switches reduce collisions and improve bandwidth use on network segments because they provide dedicated bandwidth to each network segment.

6)Q: Which are the two forwarding methods of Switches
A: Store-and-forward switching
A: Cut-through switching.

7)Q: What is the difference between Symmetric and Asymmetric Switching
A: Symmetric switching provides switched connections between ports with the same bandwidth.
A: Asymmetric switching provides switched connections between ports of unlike bandwidth.

8)Q: WHich are the two methods of memory buffering
A: Port-based memory
A: Shared-memory

9)Q: Which are the two types of Switches
A: Layer 2 and Layer 3

10)Q: Which are the two ways to configure a Cisco Device
A: Console Terminal
A: Remote Terminal

11)Q: Which three methods can be used to access the device once configured
A: Establish a terminal (VTY) session using Telnet
A: Configure the device through the current connection(console,auxiliary), or download a previously written startup-config file from a tftp server.
A: Download a configuration file using a network management software application such as CiscoWorks

12)Q: Which are the two IOS CLI EXEC sessions
A: User EXEC mode
A: Privileged EXEC mode

13)Q: Which are the characteristics of User EXEC mode
A: Access to only a limited number of basic monitoring and troubleshooting commands(show,ping)

14)Q: Which are the characteristics of Priviledge EXEC mode
A: Full access to all device commands, including configuration and management.

15)Q: Which are the two types of help available on the Cisco CLI
A: Word Help
A: Command syntax help

16)Q: Which are the most common cisco IOS syntax message errors
A: Ambiguous command
A: Incomplete command
A: Invalid input Detected at ‘^’

17)Q: How many commands does Cisco IOS stores by default
A: Cisco IOS , by default stores the last 10 commands you entered in a history buffer.

18)Q: Which commands are used regarding the Command history buffer
A: show history
A: terminal history
A: terminal history size 50
A: terminal no history size
A: terminal no history

19)Q: Which are some typical show commands
A: show version
A: show running-config
A: show flash
A: show interface
A: show processes CPU
A: show protocols
A: show memory
A: show stacks
A: show buffers
A: show startup-config

20)Q: Which are the Cisco device memory types
A: RAM
A: Flash
A: ROM
A: NVRAM

21)Q: Which is the name of the two main IOS cisco configuration files
A: startup-config
A: Running-config

22)Q: In which other place can configuration files be stored
A: on a TFTP server.

23)Q: Which are the older commands used to erased NVRAM config files
A: write erase
A: erase startup-config

24)Q: Which is the new command
A: erase nvram:

Day 28

Chapter : Connecting Switches and ethernet technology

CCNA 640-802 Topics
-Explain Technologies and media acces control method for ethernet networks
-Select the appropiate media,cables,ports and connectors to connect switches to other network devices and hosts.

1)Q: What does Ethernet and 802.3 refer to
A: Ethernet and 802.3 both refer to a family of standards that together define the physical and data link layes of the definitive LAN technology.

2)Q: In which two sublayers is Ethernet divided
A: LLC 802.2 ( Logical link Control )
A: MAC 802.3 ( Media access control ).

3)Q: What does the LLC sublayer does
A: The LLC sublayer handles communication between the network layer and the MAC sublayer.In general, LLC, provides a way to identify the protocol, that is passed from the data link layer to the network layer.

4)Q: What does the MAC sublayer does
A: Data encapsulation
A: Media access control (CSMA/CD).

5)Q: Which are the two early legacy ethernet implementations
A: 10BASE2, 10BASE5

6)Q: What does CSMA/CD means
A: Carrier Sense Multiple Acess Collision Detection.

7)Q: What does CSMA/CD algorithm defines
A: CSMA/CD algorithm defines how the ethernet logical bus is accessed

8)Q: How does the CSMA/CD algorithm Works
A: 1) A device with a frame to send listens until the ethernet is not busy
A: 2) When the Ethernet is not busy, the sender(s) begin(s) sending the frame
A: 3) The senders(s) listen(s) to make sure that no collision occurred.
A: 4) If a collision occurs, the devices that had been sending a frame each send a jamming signal to ensure that all stations recognize the collision
A: 5) After jamming is complete, each sender randomizes a timer and waits that long before trying to resend the collided frame.
A: 6) When each random timer expires, the process starts again from the beginning.

9)Q: In what state is a NIC  when using CSMA/CD
A: in Half-duplex mode.

10)Q: Does Full-duplex mode uses CSMA/CD
A: no, in full-duplex a NIC can send and receive simultaneously

11)Q: What are Hubs
A: Hubs are repeaters that provide a centralized connection point for UTP cabling, but they still create a single electrical bus, shared by the various devices, just like 10BASE5 and 10BASE2

12)Q: Which are the most common IEEE Etherner Standards
A: 802.3 (10mbps)
A: 802.3u (Fast Ethernet 100mbps).
A: 802.3z (Gigabit Ethernet 1000mbps-Fiber).
A: 802.3ab (Gigabit Ethernet 1000mbps-copper).
A: 802.3ae ( 10-GE ethernet fiber)
A: 802.3an ( 10-GE Ethernet Copper).

13)Q: Which is the standard for Straight-through and Crossover cable
A: TIA/EIA T568B(Straight-through) and TIA/EIA T568A(Crossover).

14)Q: What do Switches do, in comparison with Hub devices
A: Switches interpret the bits in the received frame so that thet can typically send the frame out the one required port , rather than all ports(Hubs behaviour…).
A: If a switch needs to forward multiple frames out the same port, the switch buffers the frames in memory, sending one at a time, thereby avoiding collisions.
A: Switches segments collisions domain(creates).

15)Q: WHich are the components of a IEEE MAC address
A: OUI+Manufacturer assigned address

16)Q: What is OUI
A: Organizationally Unique Identifier

17)Q: WHich are the Other Types of MAC addresses
A: Broadcast and Multicast

18)Q: Which are the fields of the last version ethernet frame(IEEE 802.3, 1997 revision).
A: Preamble
A: SFD ( Start Frame Delimeter)
A: Destination MAC address
A: Source MAC address
A: Length/Type ( one of both, not the two).
A: Data and Pad
A: FCS(Frame Check Sequence).

19)Q: Which are the three basic forms of Networking media
A:Copper Cable
A:Fiber
A:Wireless(IEEE 802.11).

20)Q: How are bits represented on the medium
A: Amplitude
A: Frequency
A: Phase

Day 29

Chapter : Network Data flow From end-to-end

CCNA 640-802 Exam Topics
-Use the OSI and TCP/IP models and their associated protocols yo explain how data flows in a network
-Determine the path between two hosts across a network
-Identify and correct common network problems at Layers 1,2,3, and 7 using layered model approach.

1)Q: What does the Application layer of the TCP/IP model does
A: The application layer of the TCP/IP model provides an interface between software, like a web browser, and the network itself.

2)Q: What does the Transport layer of the TCP/IP model does
A: The transport layer, through TCP, provides a mechanism yo guarantee delivery of data across the network.

3)Q: How does TCP supports error recovery
A: TCP supports error recovery to the application layer through the use of basic acknowledgment logic.

4)Q: Which are the step of TCP operation ( Web Requesting).
A: Web client sends an HTTP request for a specific Web server down to the transport layer
A: TCP encapsulates the HTTP request with a TCP header.
A: Lower Layers process and send the request to the web server.
A: Web server receives HTTP requests and sends a TCP acknowledgment back o the requesting web client.
A:Web server sends the HTTP response down to the transport layer.
A: TCP encapsulates the HTTP data with a TCP header.
A: Lower layers process and send the response to the requesting web client.
A: Requesting web client sends acknowledgment back to the web server.

5)Q: Which are the TCP/IP transport layer features (TCP/UDP).
A: Multiplexing using ports (TCP/UDP).
A: Error Recovery,reliability (TCP).
A: Flow control using windowing (TCP).
A: Connection establishment and termination(TCP)
A: Ordered data transfer and data segmentation(TCP).

6)Q: How is Error recovery implemented in TCP
A: The sequence and acknowledgment fields in the TCP header are used to track every byte of data transfer and ensure that missing bytes are retransmitted

7)Q: How is flow control Implemented in TCP
A: Flow control is handled by TCP through a process called windowing. The two end devices negotiate the window size when initially establishing the connection; then they dynamically renegotiate window size during the life of the connection, increasing  its size until it reaches the maximum windows size of 65,535 bytes or until errors occur.

8)Q: What is the Three way Handshake
A: Is the process of initializing sequence and acknowledgment  fields and agreeing on port numbers and window size.

9)Q: What happens when data transfer ends
A: After data transfer is complete, a four-way termination sequence occurs that uses a flag, called the FIN bit.

10)Q: Which are the Five steps of data encapsulation
A: Data ( application layer)
A: TCP-DATA ( at the transport layer)
A: IP-TCP-DATA ( internet layer)
A: LH(data link header)-IP-TCP-DATA-LT(data link trailer).
A: Bits! ( physical layer).

11)Q: Which are the Three troubleshooting methods
A: Bottom Up
A: Top Down
A: Divide and Conquer

Chapter 2 : Network Models and Applications (day 30).

CCNA 640-802 Exam topics:
-Describe common networked applications, including web applications
-Describe the purpose and basic operation of the protocols in the OSI and TCP models
-Describe the impact of applications(Voice over IP and Video over IP) on a network.

1)Q: Which are the 7 layers of the OSI model
A: Application
A: Presentation
A: Session
A: Transport
A: Network
A: Data Link
A: Physical

2)Q: Which are the 4 Layers of the TCP/IP model
A: Application
A: Transport
A: Internet
A: Network Access

3)Q: Which are some protocols that works at the application layer
A: DNS,Telnet,SMTP,POP3,IMAP,DHCP,HTTP,FTP,SNMP.

4)Q: Which are the main protocols of the transport layer
A: TCP/UDP

5)Q: Which are the main protocols of the network layer
A: IP,ARP,ICMP

6)Q: Which are some protocols that works at layer 2
A: Ethernet,Frame-relay,HDLC,PPP.

7)Q: What is a PDU(Protocol Data Unit).
A: As Application data is passed down the protocol stack on its way to be transmitted across the network media, various protocols add information to it a each level. This is commonly known as the encapsulation proccess.The data structure at any given layer is called a protocol data unit (PDU).

8)Q: Which are the PDUs of each layer
A: Application (Data)
A: Presentation (Data)
A: Session (Data)
A: Transport (Segment)
A: Network (Packet)
A: Data link (Frame)
A: Physical (bits).

9)Q: Which are the main considerations for VOIP
A: Low Delay
A: Low Jitter
A: Loss

Day 31

Chapter: Network devices, components and diagrams

CCNA 640-802 Exam Topics:

-Describe the purpose and functions of various network devices
-Select the components required to meet a network specification
-Describe the components required for network and internet communications.
-Interpret network diagrams
-Differentiate between LAN/WAN operation and features.

1)Q: Which devices are used to connect end devices to a single LAN
A: Hubs and Switches

2)Q: Which are the difference between switches and Hubs, and which is prefered
A: Hubs are typically chosen as an intermediary device within a very small LAN where bandwidth usage is not and issue or cost limit
A: Switches are preferred over hubs as a LAN intermediary device because a switch can segment collision domain and provide enhanced security

3)Q: Which are the main factors to consider when choosing a switch
A: Cost
A: Interface characteristics
A: Hierarchical network layer

13)Q: Which are the three most common networking media in use today
A: Copper
A: Fiber optics
A: Wireless

14)Q: What needs to be considered when choosing media
A: Cable length
A: Cost
A: Bandwidth
A: Ease of installation
A: Susceptible to EMI/RFI

25)Q: WHich are the modules of the Enterprise Network Module
A: Enterprise Campus architecture
A: Enterprise Edge architecture
A: Enterprise Branch architecture
A: Enterprise Data Center Architecture
A: Enterprise Teleworker Architecture

26)Q: Which major categories should a Documentation Include
A: Router and Switch Documentation
A: End-Systems docuumentation
A: Network Topology Diagram

27)Q: Which commands are useful for Documentation Purposes
A: Ping
A: Telnet
A: show ip interface brief
A: show ip route
A: show cdp neighbor detail

Well regarding my CCNA Studies, i have decided to use the same method i used for JNCIS-SEC , Q&A posts, as i go through every subject in the guide i`ll be posting every note. They will be divided in days again, cause i`m using 31 days before your CCNA exam CIsco press book, so you should expect a greater not deeper overview of the chapters, cause this is more a review than a total study of CCNA. There will be some exceptions to this rule, regarding Notes and How to guides, there i will try to get the deepest i can (in ccna level!), so yes there will be Practice guides .

That is all for now, feel free to comment any post, any error!