程序代写代做代考 DHCP cache IOS dns ITE PC v4.0 Chapter 1

ITE PC v4.0 Chapter 1

CE231 Autumn Term

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
CE231 Course overview
Autumn Term
CCNA Routing & Switching Essentials
Assignment 1 (12.5% of module), Packet Tracer based assignment
CCNA Final Exam, MCQ test (12.5% of module)

Spring Term
CCNA Routing & Switching: Scaling Networks
Assignment 2 (12.5% of module), Packet Tracer based assignment
CCNA Final Exam, MCQ test (12.5% of module)

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
How to use these notes
Remember: these are lecture “Notes”, they are not a complete coverage of every detail. You will need to:
Attend the lectures and add annotation
Read the Chapter contents in either the recommended reading or the Cisco courseware (each are equally good).
In book form See: Cisco Networking Academy, Routing and Switching Essentials Companion Guide (Cisco Press, 2014, 2nd edition)
Attempt all of the Chapter exams and the laboratory exercises
Attempt as many of the Chapter Packet Tracer activities as possible, but in particular those suggested during the lectures.
Some fonts may be too small on these Cisco supplied slides: the lecture will highlight and zoom in to key parts – you may need to read online if some parts are too small on the printed version.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
Chapter 1: Routing Concepts
Routing and Switching Essentials v6.0

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
4

Chapter 1 – Sections & Objectives
1.1 Router Initial Configuration
Describe the primary functions and features of a router.
Configure basic settings on a router to route between two directly-connected networks, using CLI.
Verify connectivity between two networks that are directly connected to a router.
1.2 Routing Decisions
Explain the encapsulation and de-encapsulation process used by routers when switching packets between interfaces.
Explain the path determination function of a router.
1.3 Router Operation
Explain routing table entries for directly connected networks.
Explain how a router builds a routing table of directly connected networks.
Explain how a router builds a routing table using static routes.
Explain how a router builds a routing table using a dynamic routing protocol.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
5

1.1 Router Initial Configuration

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
6
Cisco Networking Academy Program
Routing and Switching Essentials v6.0
Chapter 1: Dynamic Routing

Router Functions
Characteristics of a Network

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
7
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.1 – Characteristics of a Network

Router Functions
Why Routing?
The router is responsible for the routing of traffic between networks.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
8
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.2 – Why Routing?

Routers are specialized computers containing the following required components to operate:
Central processing unit (CPU)
Operating system (OS) – Routers use Cisco IOS
Memory and storage (RAM, ROM, NVRAM, Flash, hard drive)

Router Functions
Routers are Computers

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
9
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.3 – Routers are Computers

Routers use specialized ports and network interface cards to interconnect to other networks.
Router Functions
Routers are Computers (cont.)

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
10
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.3 – Routers are Computers (cont.)

Router Functions
Routers are Computers

Router Memory

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
11
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.3 – Routers are Computers

Router Functions
Routers Interconnect Networks

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
12
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.4 Routers Interconnect Networks

Router Functions
Routers Choose Best Paths
Routers use static routes and dynamic routing protocols to learn about remote networks and build their routing tables.
Routers use routing tables to determine the best path to send packets.
Routers encapsulate the packet and forward it to the interface indicated in routing table.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
13
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.5 Routers Choose Best Paths

Process switching – An older packet forwarding mechanism still available for Cisco routers.
Fast switching – A common packet forwarding mechanism which uses a fast-switching cache to store next hop information.
Cisco Express Forwarding (CEF) – The most recent, fastest, and preferred Cisco IOS packet-forwarding mechanism.
Router Functions
Packet Forwarding Methods

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
14
1.1 – Router Initial Configuration
1.1.1 – Router Functions
1.1.1.6 – Packet Forwarding Methods

Connect Devices
Connect to a Network

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
15

1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.1 – Connect to a Network

Connect Devices
Default Gateways

To enable network access devices, must be configured with the following IP address information:
IP address – Identifies a unique host on a local network.
Subnet mask – Identifies the host’s network subnet.
Default gateway – Identifies the router a packet is sent to when the destination is not on the same local network subnet.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
16
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.2 – Default Gateways

Connect Devices
Document Network Addressing
Network documentation should include at least the following in a topology diagram and addressing table:
Device names
Interfaces
IP addresses and
subnet masks
Default gateways

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
17
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.3 – Document Network Addressing

Connect Devices
Enable IP on a Host
Statically Assigned IP address – The host is manually assigned an IP address, subnet mask and default gateway. A DNS server IP address can also be assigned.
Used to identify specific network resources such as network servers and printers.
Can be used in very small networks with few hosts.

Dynamically Assigned IP Address – IP Address information is dynamically assigned by a server using Dynamic Host Configuration Protocol (DHCP).
Most hosts acquire their IP address information through DHCP.
DHCP services can be provided by Cisco routers.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
18
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.4 – Enable IP on a Host

Connect Devices
Enable IP on a Host

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
19
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.4 – Enable IP on a Host

Connect Devices
Enable IP on a Host

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
20
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.4 – Enable IP on a Host

Connect devices
Device LEDs

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
21
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.5 – Device LEDs

Console Access

Connect Devices
Console Access

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
22
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.6 – Console Access

Connect Devices
Enable IP on a Switch
Network infrastructure devices require IP addresses to enable remote management.
On a switch, the management IP address is assigned on a virtual interface called a switched virtual interface (SVI)

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
23
1.1 – Router Initial Configuration
1.1.2 – Connect Devices
1.1.2.7 – Enable IP on a Switch

Router Basic Settings
Configure Router Basic Settings
Name the device – Distinguishes it from other routers
Secure management access – Secures privileged EXEC, user EXEC, and Telnet access, and encrypts passwords .
Configure a banner – Provides legal notification of unauthorized access.
Save the Configuration

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
24
1.1 – Router Initial Configuration
1.1.3 – Router Operation
1.1.3.1 – Configure Router Basic Settings

Router Basic Settings
Configure an IPv4 Router Interface
To be available, a router interface must be:
Configured with an address and subnet mask.
Activated using no shutdown command. By default LAN and WAN interfaces are not activated.
Configured with the clock rate command on the Serial cable end labeled DCE.
Optional description can be included.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
25
1.1 – Router Initial Configuration
1.1.3 – Router Operation
1.1.3.2 – Configure an IPv4 Router Interface

Router Basic Settings
Configure an IPv6 Router Interface
Configure interface with IPv6 address and subnet mask:
Use the ipv6 address ipv6-address/ipv6-length [link-local | eui-64]interface configuration command.
Activate using the no shutdown command.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
26
1.1 – Router Initial Configuration
1.1.3 – Router Operation
1.1.3.3 – Configure an IPv6 Router Interface

Router Basic Settings
Configure an IPv6 Router Interface (cont.)
IPv6 interfaces can support more than one address:
Configure a specified global unicast – ipv6address ipv6-address /ipv6-length
Configure a global IPv6 address with an interface identifier (ID) in the low-order 64 bits – ipv6address ipv6-address /ipv6-length eui-64
Configure a link-local address – ipv6address ipv6-address /ipv6-length link-local

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
27
1.1 – Router Initial Configuration
1.1.3 – Router Operation
1.1.3.3 – Configure an IPv6 Router Interface (cont.)

Router Basic Settings
Configure an IPv4 Loopback Interface
A loopback interface is a logical interface that is internal to the router:
It is not assigned to a physical port, it is considered a software interface that is automatically in an UP state.
A loopback interface is useful for testing.
It is important in the OSPF routing process.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
28
1.1 – Router Initial Configuration
1.1.3 – Router Operation
1.1.3.4 – Configure an IPv4 Loopback Interface

Verify Connectivity of Directly Connected Networks
Verify Interface Settings
Show commands are used to verify operation and configuration of interface:
show ip interfaces brief
show ip route
show running-config
Show commands that are used to gather more detailed interface information:
show interfaces
show ip interfaces

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
29
1.1 – Router Initial Configuration
1.1.4 – Verify Connectivity of Directly Connected Networks
1.1.4.1 – Verify Interface Settings

Verify Connectivity of Directly Connected Networks
Verify Interface Settings (cont.)

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
30
1.1 – Router Initial Configuration
1.1.4 – Verify Connectivity of Directly Connected Networks
1.1.4.1 – Verify Interface Settings (cont.)

Verify Connectivity of Directly Connected Networks
Verify IPv6 Interface Settings
Common commands to verify the IPv6 interface configuration:
show ipv6 interface brief – displays a summary for each of the interfaces.
show ipv6 interface gigabitethernet 0/0 – displays the interface status and all the IPv6 addresses for this interface.
show ipv6 route – verifies that IPv6 networks and specific IPv6 interface addresses have been installed in the IPv6 routing table.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
31
1.1 – Router Initial Configuration
1.1.4 – Verify Connectivity of Directly Connected Networks
1.1.4.2 – Verify IPv6 Interface Settings

Show command output can be managed using the following command and filters:
Use the terminal length number command to specify the number of lines to be displayed.
To filter specific output of commands use the (|)pipe character after show command. Parameters that can be used after pipe include:
section, include, exclude, begin

Verify Connectivity of Directly Connected Networks
Filter Show Command Output

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
32
1.1 – Router Initial Configuration
1.1.4 – Verify Connectivity of Directly Connected Networks
1.1.4.3 – Filter Show Command Output

Verify Connectivity of Directly Connected Networks
Command History Feature
The command history feature temporarily stores a list of executed commands for access:
To recall commands press Ctrl+P or the UP Arrow.
To return to more recent commands press Ctrl+N or the Down Arrow.
By default, command history is enabled and the system captures the last 10 commands in the buffer. Use the show history privileged EXEC command to display the buffer contents.
Use the terminal history size user EXEC command to increase or decrease size of the buffer.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
33
1.1 – Router Initial Configuration
1.1.4 – Verify Connectivity of Directly Connected Networks
1.1.4.4 – Command History Feature

1.2 Routing Decisions

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
34
1.2 – Routing Decisions

Switching Packets Between Networks
Router Switching Function

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
35
1.2 – Routing Decisions
1.2.1 – Switching Packets Between Networks
1.2.1.1 – Router Switching Function

Switching Packets Between Networks
Send a Packet

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
36
1.2 – Routing Decisions
1.2.1 – Switching Packets Between Networks
1.2.1.2 – Send a Packet

Switching Packets Between Networks
Forward to Next Hop

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
37
1.2 – Routing Decisions
1.2.1 – Switching Packets Between Networks
1.2.1.3 – Forward to Next Hop

Switching Packets Between Networks
Packet Routing

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
38
1.2 – Routing Decisions
1.2.1 – Switching Packets Between Networks
1.2.1.4 – Packet Routing

Switching Packets Between Networks
Reach the Destination

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
39
1.2 – Routing Decisions
1.2.1 – Switching Packets Between Networks
1.2.1.5 – Reach the Destination

Path Determination
Routing Decisions

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
40
1.2 – Routing Decisions
1.2.2 – Path Determination
1.2.2.1 – Routing Decisions

Path Determination
Best Path
Best path is selected by a routing protocol based on the value or metric it uses to determine the distance to reach a network:
A metric is the value used to measure the distance to a given network.
Best path to a network is the path with the lowest metric.
Dynamic routing protocols use their own rules and metrics to build and update routing tables:
Routing Information Protocol (RIP) – Hop count
Open Shortest Path First (OSPF) – Cost based on cumulative bandwidth from source to destination
Enhanced Interior Gateway Routing Protocol (EIGRP) – Bandwidth, delay, load, reliability

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
41
1.2 – Routing Decisions
1.2.2 – Path Determination
1.2.2.2 – Best Path

Path Determination
Load Balancing
When a router has two or more paths to a destination with equal cost metrics, then the router forwards the packets using both paths equally:
Equal cost load balancing can improve network performance.
Equal cost load balancing can be configured to use both dynamic routing protocols and static routes.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
42
1.2 – Routing Decisions
1.2.2 – Path Determination
1.2.2.3 – Load Balancing

Path Determination
Administrative Distance
If multiple paths to a destination are configured on a router, the path installed in the routing table is the one with the lowest Administrative Distance (AD):
A static route with an AD of 1 is more reliable than an EIGRP-discovered route with an AD of 90.
A directly connected route with an AD of 0 is more reliable than a static route with an AD of 1.

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
43
1.2 – Routing Decisions
1.2.2 – Path Determination
1.2.2.4 – Administrative Distance

1.3 Router Operation

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
44

Analyze the Routing Table
The Routing Table
A routing table is a file stored in RAM that contains information about:
Directly connected routes
Remote routes

Presentation_ID
‹#›
© 2008 Cisco Systems, Inc. All rights reserved.
Cisco Confidential
45
1.3 – Router Operation
1.3.1 – Analyze the Routing Table
1.3.1.1 – The Routing Table

Analyze the Routing Table
Routing Table Sources
The show ip route command is used to display the contents of the routing table:
Local route interfaces – Added to the routing table when an interface is configured. (displayed in IOS 15 or newer for IPv4 routes and all IOS releases for IPv6 routes.)
Directly connected interfaces – Added to the routing table when an interface is configured and active.
Static routes – Added when a route is manually configured and the exit interface is active.
Dynamic routing protocol – Added when EIGRP or OSPF are implemented and networks are identified.

Analyze the Routing Table
Routing Table Sources (cont.)

Analyze the Routing Table
Remote Network Routing Entries

Interpreting the entries in the routing table

Directly Connected Routes
Directly Connected Interfaces
A newly deployed router, without any configured interfaces, has an empty routing table.

Directly Connected Routes
Directly Connected Routing Table Entries

Directly Connected Routes
Directly Connected Example

Directly Connected Routes
Directly Connected IPv6 Example

Statically Learned Routes
Static Routes
Static routes and default static routes can be implemented after directly connected interfaces are added to the routing table:
Static routes are manually configured.
They define an explicit path between two networking devices.
Static routes must be manually updated if the topology changes.
Their benefits include improved security and control of resources.
Configure a static route to a specific network using the ip route network mask {next-hop-ip | exit-intf} command.
A default static route is used when the routing table does not contain a path for a destination network.
Configure a default static route using the ip route 0.0.0.0 0.0.0.0 {exit-intf | next-hop-ip} command.

Statically Learned Routes
Static Route Example

Statically Learned Routes
Static Route Example (cont.)

Entering and Verifying a Static Route

Statically Learned Routes
Static IPv6 Route Examples

Dynamic Routing Protocols
Dynamic Routing
Dynamic routing is used by routers to share information about the reachability and status of remote networks.
It performs network discovery and maintains routing tables.
Routers have converged after they have finished exchanging and updating their routing tables.

Dynamic Routing Protocols
IPv4 Routing Protocols
Cisco routers can support a variety of dynamic IPv4 routing protocols including:
EIGRP – Enhanced Interior Gateway Routing Protocol
OSPF – Open Shortest Path First
IS-IS – Intermediate System-to-Intermediate System
RIP – Routing Information Protocol
Use the router ? Command in global configuration mode to determine which routing protocols are supported by the IOS.

Dynamic Routing Protocols
IPv4 Dynamic Routing Examples

Dynamic Routing Protocols
IPv6 Routing Protocols
Cisco routers can support a variety of dynamic IPv6 routing protocols including:
RIPng (RIP next generation)
OSPFv3
EIGRP for IPv6
Use the ipv6 router ? command to determine which routing protocols are supported by the IOS

IPv6 Routing Protocols

Dynamic Routing Protocols
IPv6 Dynamic Routing Examples

1.4 Chapter Summary

Describe the primary functions and features of a router.
Configure basic settings on a router to route between two directly-connected networks, using CLI.
Verify connectivity between two networks that are directly connected to a router.
Explain how routers use information in data packets to make forwarding decisions in a small to medium-sized business network.
Explain the encapsulation and de-encapsulation process used by routers when switching packets between interfaces.
Explain the path determination function of a router.
Explain how a router learns about remote networks when operating in a small to medium-sized business network.
Explain how a router builds a routing table of directly connected networks.
Explain how a router builds a routing table using static routes.
Explain how a router builds a routing table using a dynamic routing protocol.

Chapter Summary
Summary

/docProps/thumbnail.jpeg

Related Posts