Chapter 4: Routing Concepts Routing Protocols Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Chapter 4.0 Routing Concepts 4.1 Initial Configuration of a Router 4.2 Routing Decisions 4.3 Routing Operation 4.4 Summary Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Chapter 4: Objectives Configure a router to route between multiple directly connected networks Describe the primary functions and features of a router Explain how routers use information in data packets to make forwarding decisions in a small to medium-sized business network Presentation_ID Explain the encapsulation and de-encapsulation process used by routers when switching packets between interfaces Compare ways in which a router builds a routing table when operating in a small to medium-sized business network Explain routing table entries for directly connected networks Explain how a router builds a routing table of directly connected networks © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Chapter 4: Objectives (continued) Presentation_ID Explain how a router builds a routing table using static routes Explain how a router builds a routing table using a dynamic routing protocol © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Functions of a Router Characteristics of a Network Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Functions of a Router Why Routing? Presentation_ID The router is responsible for the routing of traffic between networks © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Functions of a Router Routers are Computers 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) Presentation_ID Routers utilize the following memory: © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Functions of a Router Routers are Computers Presentation_ID Routers use specialized ports and network interface cards to interconnect to other networks © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Functions of a Router Routers Interconnect Networks Presentation_ID Routers can connect multiple networks Routers have multiple interfaces, each on a different IP network © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential Functions of a Router Routers Choose Best Paths Determine the best path to send packets Uses its routing table to determine path Forward packets toward their destination Forwards packet to interface indicated in routing table Encapsulates the packet and forwards out toward destination Routers use static routes and dynamic routing protocols to learn about remote networks and build their routing tables Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 10 Anatomy of a Router Connecting to a Router WAN AUX LAN Interface port interfaces Console RJ45 Console USB Type B Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 59 Anatomy of a Router LAN and WAN Interfaces Serial interfaces LAN interfaces Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 60 Router Boot-up Cisco IOS Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 61 Router Boot-up Bootset Files Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 62 Router Boot-up Router Bootup Process Perform the POST and load the bootstrap program Locate and load the Cisco IOS software Locate and load the startup configuration file or enter setup mode System Bootstrap, Version 15.0(1r)M15, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 63 Router Boot-up Show Versions Output Router# show version Cisco IOS Software, C1900 Software (C1900-UNIVERSALK9-M), Version 15.2(4)M1, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2012 by Cisco Systems, Inc Compiled Thu 26-Jul-12 19:34 by prod_rel_team ROM: System Bootstrap, Version 15.0(1r)M15, RELEASE SOFTWARE (fc1) Router uptime is 10 hours, minutes System returned to ROM by power-on System image file is "flash0:c1900-universalk9-mz.SPA.152-4.M1.bin" Last reload type: Normal Reload Last reload reason: power-on Cisco CISCO1941/K9 (revision 1.0) with 446464K/77824K bytes of memory Processor board ID FTX1636848Z Gigabit Ethernet interfaces Serial(sync/async) interfaces terminal line DRAM configuration is 64 bits wide with parity disabled 255K bytes of non-volatile configuration memory 250880K bytes of ATA System CompactFlash (Read/Write) Technology Package License Information for Module:'c1900' Technology Technology-package Technology-package Current Next reboot Type -ipbase ipbasek9 Permanent ipbasek9 security None None None data None None None Configuration register is 0x2142 (will be 0x2102 at next reload) Router# Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 64 Network Layer Configuring a Cisco Router Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 65 Configure Initial Settings Router Configuration Steps 192.168.10.0/24 10 10.1.1.0/24 G0/0 PC1 226 225 R1 10 10 209.165.200.224 /30 R2 S0/0/0 10 G0/1 PC2 10.1.2.0/24 192.168.11.0/24 Router> en Router> enable Router# conf t Router# configure terminal Enter configuration commands, one per line Enter configuration commands, one per line End with CNTL/Z Router(config)# hostname R1 OR R1(config)# R2(config)# R1(config)# enable secret class R1(config)# banner motd # R1(config)# Enter TEXT message R1(config)# line console End with the character '#' *********************************************** R1(config-line)# password cisco WARNING: Unauthorized access is prohibited! R1(config-line)# login R1(config-line)# exit End with CNTL/Z Router(config)# ho R1 *********************************************** # R1(config)# R1(config)# line vty R1(config)# R1(config-line)# password cisco R1(config-line)# login R1(config-line)# exit R1(config)# R1# copy running-config startup-config R1(config)# service password-encryption Destination filename [startup-config]? R1(config)# Building configuration [OK] R1# Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 66 Configure Interfaces Configure LAN Interfaces 192.168.10.0/24 10 10.1.1.0/24 G0/0 PC1 225 R1 10 10 209.165.200.224 /30 226 R2 S0/0/0 10 G0/1 PC2 10.1.2.0/24 192.168.11.0/24 R1# conf t Enter configuration commands, one per line End with CNTL/Z R1(config)# R1(config)# interface gigabitethernet 0/0 R1(config-if)# ip address 192.168.10.1 255.255.255.0 R1(config-if)# description Link to LAN-10 R1(config-if)# no shutdown %LINK-5-CHANGED: Interface GigabitEthernet0/0, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up R1(config-if)# exit R1(config)# R1(config)# int g0/1 R1(config-if)# ip add 192.168.11.1 255.255.255.0 R1(config-if)# des Link to LAN-11 R1(config-if)# no shut %LINK-5-CHANGED: Interface GigabitEthernet0/1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to up R1(config-if)# exit R1(config)# Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 67 Configure Interfaces Verify Interface Configuration 192.168.10.0/24 10 10.1.1.0/24 G0/0 PC1 226 225 R1 10 10 209.165.200.224 /30 R2 S0/0/0 10 G0/1 PC2 10.1.2.0/24 192.168.11.0/24 R1# show ip interface brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 192.168.10.1 YES manual up up GigabitEthernet0/1 192.168.11.1 YES manual up up Serial0/0/0 209.165.200.225 YES manual up up Serial0/0/1 unassigned YES NVRAM administratively down down Vlan1 unassigned YES NVRAM administratively down down R1# R1# ping 209.165.200.226 Type escape sequence to abort Sending 5, 100-byte ICMP Echos to 209.165.200.226, timeout is seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/9 ms R1# Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 68 Configuring a Cisco Router Configuring the Default Gateway Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 69 Configuring the Default Gateway Default Gateway on a Host 10 PC1 192.168.10.0/24 G0/0 10 PC2 R1 G0/1 10 PC1 10 192.168.10.0/24 PC3 10 192.168.11.0/24 G0/0 11 PC2 PC4 R1 G0/1 10 PC3 11 192.168.11.0/24 PC4 Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 70 Configuring the Default Gateway Default Gateway on a Switch S1#show running-config Building configuration ! service password-encryption ! hostname S1 ! Interface Vlan1 ip address 192.168.10.50 ! ip default-gateway 192.168.10.1 10 PC1 192.168.11.0/24 192.168.10.0/24 11 PC2 G0/0 S1 R1 G0/1 S2 50 If the default gateway were not configured on S1, response packets from S1 would not be able to reach the administrator at 192.168.11.10 The administrator would not be able to mange the device remotely Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 71 Chapter 4: Summary Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 72 Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 73 ...Chapter 4.0 Routing Concepts 4.1 Initial Configuration of a Router 4.2 Routing Decisions 4.3 Routing Operation 4.4 Summary Presentation_ID © 2008 Cisco... Confidential 38 The Routing Table Routing Table Sources Show ip route command is used to display the contents of the routing table Link local Interfaces –Added to the routing table when an... Confidential 39 The Routing Table Routing Table Sources Presentation_ID © 2008 Cisco Systems, Inc All rights reserved Cisco Confidential 40 The Routing Table Remote Network Routing Entries Presentation_ID