intTypePromotion=1
zunia.vn Tuyển sinh 2024 dành cho Gen-Z zunia.vn zunia.vn
ADSENSE
 » 
 » 

Giao thức định tuyến - Chapter 2

Chia sẻ: HA KIEN | Ngày: | Loại File: PDF | Số trang:64

Thêm vào BST
Báo xấu
111
lượt xem 14
download
 
  Download Vui lòng tải xuống để xem tài liệu đầy đủ

Define the ge e a role a router p ays in networks. e e e general o e ou e plays e o s Describe the directly connected networks, different router interfaces Examine directly connected networks in the routing table and use the CDP protocol Describe static routes with exit interfaces Describe summary and default route Examine how packets get forwarded when using static routes Identify how to manage and troubleshoot static routes.

Chủ đề:

Bình luận(0) Đăng nhập để gửi bình luận!

Lưu

Nội dung Text: Giao thức định tuyến - Chapter 2

  1. Static Routing Routing Protocols and Concepts – Chapter 2 ITE PC v4.0 1 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  2. Objectives Define the general role a router plays in networks. ge Describe the directly connected networks, different router interfaces router interfaces Examine directly connected networks in the routing table and use the CDP protocol table and use the CDP protocol Describe static routes with exit interfaces Describe summary and default route Examine how packets get forwarded when using static routes Identify how to manage and troubleshoot static routes ITE PC v4.0 2 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  3. General Role of the Router Functions of a Route er Best Path Selections Forwarding packets to destination Routers perform packet forwarding by learning about remote networks and maintaining routing information. – The routers primary forwarding decision is based on Layer 3 information, the destination IP address. – The router's routing table is used to find the best match between the destination IP of a packet and a network address in the routing table. – The routing table will ultimately determine the exit interface to forward the packet and the router will encapsulate that packet in the appropriated data link frame for that outgoing interface the appropriated data link frame for that outgoing interface. ITE PC v4.0 3 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  4. General Role of the Router Introducing the Topology – The figure shows the topology used in this chapter. – 3 1800 series routers connected via WAN links – Each router connected to a LAN represented by a switch and a PC ITE PC v4.0 4 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  5. General Role of the Router Connections of a Router for WAN -A router has a DB-60 port that can support 5 different cabling standards –Newer routers support the smart serial pp interface that allows for more data to be forwarded across fewer cable pins. Connections of a Router for Ethernet -2 types of connectors can be used: Straight through and Cross-over Straight through used to connect: Straight through used to connect: -Switch-to-Router, Switch-to-PC, Hub-to- PC, Hub-to-Server Cross Cross-over used to connect (pin 1 connected used to connect (pin connected to pin 3, and pin 2 connected to pin 6): -Switch-to-Switch, PC-to-PC, Switch-to- Hub, Hub-to-Hub, Router-to-Router, PC- Router ITE PC v4.0 5 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  6. General Role of the Router in COD Smart Serial cables: DCE and DTE Se cab -Use straight cable to connect between DCE and DTE Adapter the DTE and DCE.. Ethernet cables: Cross-over cable: RED cable Roll-over cable: flat cables Straight cable: all other cables http://www.csdata.com/csdonline/customer/home.php ITE PC v4.0 6 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  7. Serial Connectors DTE DCE DCE DTE DTE DCE In our labs we will use serial DTE/DCE cables (no CSU/DSU) with a DTE cable connected to one router and a DCE cable connected to the other router. th ITE PC v4.0 7 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  8. Interfaces Examining Router Interfaces -Show IP router command – used to view routing table -Show Interfaces command – used to show status of an interface -Show IP Interface brief command – used to show a portion of the interface information on a condensed format -Show running-config command – used to show configuration file in RAM ITE PC v4.0 8 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  9. Interfaces Co Configuring an Ethernet interface -By default all serial and Ethernet interfaces are down -To enable an interface use the No Shutdown command •The show ip route command is used to display the routing table. •Initially, the routing table is empty if no interfaces have been configured. •Static routes and dynamic routes will not be added to th the routing table until the th appropriate local interfaces have been configured on the router the router. ITE PC v4.0 9 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  10. Verifying Ethernet interface Verifying Ethernet interface - Show interfaces - command shows the status and gives a detailed description for all interfaces on the router – Show interfaces fastEthernet 0/0 – command used to show status of fast Ethernet port •R1#show interfaces fastethernet 0/0 interfaces fastethernet 0/0 •FastEthernet0/0 is administratively down, line protocol is down • Administratively down means that the interface is currently in the shutdown mode, or turned off. •Line protocol is down means, in this case, that the interface is not receiving a carrier signal from protocol is down in this case that the interface is not receiving carrier signal from a switch or the hub. This condition may also be due to the fact that the interface is in shutdown mode • You will notice that the show interfaces command does not show any IP addresses on R1's interfaces The reason for this is because we have not yet configured IP addresses on any of the interfaces. The reason for this is because we have not yet configured IP addresses on any of the interfaces. ITE PC v4.0 10 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  11. Interfaces Interfaces Verifying Ethernet interface – Show run – run • command displays the current configuration file that the router is using. Configuration commands are temporarily stored in the running configuration file and implemented immediately by the router and implemented immediately by the router. •However, using show running-config is not necessarily the best way to verify interface configurations. -Show ip interface brief – -can be used to see a portion of the interface information in a condensed format. ITE PC v4.0 11 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  12. Configuring an Ethernet interface Configuring an Ethernet interface By default, all router interfaces are shutdown. To enable this interface, use the no shutdown command, which changes the interface from administratively down to up interface from administratively down to up. R1(config)#interface fastethernet 0/0 R1(config-if)#ip address 172.16.3.1 255.255.255.0 R1(config-if)#no shutdown The following message is returned from the IOS: *Mar 1 01:16:08.212: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up *Mar 1 01:16:09.214: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up –The first changed state to up message indicates that, physically, the connection is good. If you do not get this first message, be sure that the interface is properly connected to a carrier signal from switch or a hub. –The second changed state to up message indicates that the Data Link layer is operational. • However, WAN interfaces in a lab environment require WAN interfaces in lab environment require clocking on one side of the link. If you do correctly set the clock rate, then line protocol will not change to up. ITE PC v4.0 12 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  13. Configuring an Ethernet interface Configuring an Ethernet interface Unsolicited Messages from IOS The IOS often sends unsolicited messages. As you can see in the figure, sometimes these messages will occur when you are in the middle messages will occur when you are in the middle of typing a command, such as configuring a description for the interface. –The IOS message does not affect the command, but it can cause you to lose your place when typing. In order to keep the unsolicited output separate In order to keep the unsolicited output separate from your input, enter line configuration mode for the consoled port and add the logging synchronous command, as shown. You will see that messages returned by IOS no longer that messages returned by IOS no longer interfere with your typing. ITE PC v4.0 13 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  14. Interfaces Interfaces Verifying Ethernet interface -Show interfaces fastEthernet 0/0 Reading the Routing Table –Now look at routing table shown in the figure. Notice R1 now has a "directly connected" FastEthernet 0/0 interface a new network. –The interface was configured with the 172.16.3.1/24 IP address which makes it a member of the 172.16.3.0/24 network. 172.16.0.0/24 is subnetted, 1 subnets C 172.16.3.0 is directly connected, FastEthernet0/0 –The C at the beginning of the route indicates that this is a directly connected network. In other words, R1 has an interface that belongs to this network network. –The /24 subnet mask for this route is displayed in the line above the actual route. ITE PC v4.0 14 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  15. Interfaces Interfaces Reading the Routing Table 172.16.0.0/24 is subnetted, subnets 172.16.0.0/24 is subnetted, 1 subnets –Having a single route represent an entire network of host IP addresses makes the network of host IP addresses makes the routing table smaller, with fewer routes, which results in faster routing table lookups. •It means that this route matches all means that this route matches all packets with a destination address belonging to this network. –The routing table could contain all 254 individual host IP addresses for the IP th 172.16.3.0/24 network, but that is an inefficient way of storing addresses. ITE PC v4.0 15 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  16. Interfaces Interfaces Verifying Ethernet interface show interfaces fastethernet 0/0 show ip interface brief The show interfaces fastethernet 0/0 command in the figure now shows in the figure now shows –The interface is up, and the line protocol is up. The no shutdown command changed the interface from administratively down to up. –Notice that the IP address is now displayed. The command show ip interface brief in the figure shows that the interface is up, and the li line protocol is up. (in a condensed format) Typically, the router's Ethernet or FastEthernet interface will be the default gateway IP address for any devices on that LAN for any devices on that LAN. –For example, PC1 would be configured with a IP address belonging to the 172.16.3.0/24 network, with the default gateway IP address 172.16.3.1. –172.16.3.1 is router R1's FastEthernet IP address. ITE PC v4.0 16 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  17. Ethernet Interfaces Participate in ARP Ethernet Interfaces Participate in ARP A router's Ethernet interface participates in a LAN network just like any other device on that network device on that network. –This means that these interfaces have a Layer 2 MAC address, as shown in the figure. The show interfaces command displays the MAC MAC address for the Ethernet interfaces. th Eth –If a router has a packet destined for a device on a directly connected Ethernet network, it checks the ARP table for an entry with that destination IP address in order to map it to the MAC address. ITE PC v4.0 17 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  18. Interfaces Configuring a Serial interface Serial interface -Enter interface configuration mode -Enter in the ip address and subnet mask in the ip address and subnet mask -Enter in the no shutdown command Example: Example: -R1(config)#interface serial 0/0/0 -R1(config-if)#ip address 172.16.2.1 255.255.255.0 -R1(config-if)#no shutdown ITE PC v4.0 18 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  19. Interfaces R1(config)#interface serial 0/0/0 R1(config-if)#ip address 172.16.2.1 255.255.255.0 address 172 255 R1(config-if)#no shutdown R2(config)#interface serial 0/0/0 R2(config-if)#ip address 172.16.2.2 255.255.255.0 R2(config-if)#no shutdown –There is no requirement that both ends of the serial link use the same interface, (0/0/0, 0/0/1, 0/1/0, 0/1/1, ….) –in this case, Serial 0/0/0. However, because both interfaces are members of the same network, they both must have IP addresses that belong to the 172.16.2.0/24 network. –If we now issue the show interfaces serial 0/0/0 command on either router, we still see that we now issue the show interfaces serial 0/0/0 command on either router we still see that the link is up/down. R2#show interfaces serial 0/0/0 Serial0/0/0 is up, line protocol is down – The physical link between R1 and R2 is up because both ends of the serial link have been configured correctly with an IP address/mask and enabled with the no shutdown command. – However, the line protocol is still down. This is because the interface is not receiving a clock signal. – There is still one more command that we need to enter, the clock rate command, on the router with the DCE cable. The clock rate command will set the clock signal for the link. ITE PC v4.0 19 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
  20. Interfaces1 Step Step 3 Setup “no shut” Nothing is configured Step 2 Step 4 Configured the clock rate Setup IP but not “no shut” ITE PC v4.0 20 Chapter 1 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
ADSENSE

CÓ THỂ BẠN MUỐN DOWNLOAD

LV.15: Bộ Đồ Án Tốt Nghiệp Chuyên Ngành Cơ Khí
65 tài liệu
2430 lượt tải
THÔNG TIN
TRỢ GIÚP
HỖ TRỢ KHÁCH HÀNG
Theo dõi chúng tôi

Chịu trách nhiệm nội dung:

Nguyễn Công Hà - Giám đốc Công ty TNHH TÀI LIỆU TRỰC TUYẾN VI NA

LIÊN HỆ

Địa chỉ: P402, 54A Nơ Trang Long, Phường 14, Q.Bình Thạnh, TP.HCM

Hotline: 093 303 0098

Email: support@tailieu.vn

Giấy phép Mạng Xã Hội số: 670/GP-BTTTT cấp ngày 30/11/2015 Copyright © 2022-2032 TaiLieu.VN. All rights reserved.

 

Đồng bộ tài khoản
2=>2