Cisco Systems 1900 Series manual Gateway of Last Resort, Routerconfig# ip routing

Page 89

Chapter 5 Configuring the Router

Performing the Initial Configuration on the Router

Gateway of Last Resort

When default information is being passed along through a dynamic routing protocol, no further configuration is required. The system periodically scans its routing table to choose the optimal default network as its default route. In the case of RIP, there is only one choice, network 0.0.0.0. In the case of IGRP, there might be several networks that can be candidates for the system default. The Cisco IOS software uses both administrative distance and metric information to determine the default route (gateway of last resort). The selected default route appears in the gateway of last resort display of the show ip route EXEC command.

If dynamic default information is not being passed to the software, candidates for the default route are specified with the ip default-networkglobal configuration command. In this usage, the ip default-networkcommand takes an unconnected network as an argument. If this network appears in the routing table from any source (dynamic or static), it is flagged as a candidate default route and is a possible choice as the default route.

If the router has no interface on the default network, but does have a route to it, it considers this network as a candidate default path. The route candidates are examined and the best one is chosen, based on administrative distance and metric. The gateway to the best default path becomes the gateway of last resort.

SUMMARY STEPS

1.enable

2.configure terminal

3.ip routing

4.ip route dest-prefix mask next-hop-ip-address [admin-distance] [permanent]

5.ip default-network network-numberor

ip route dest-prefix mask next-hop-ip-address

6.end

7.show ip route

DETAILED STEPS

 

 

Command or Action

Purpose

 

Step 1

 

 

 

enable

Enables privileged EXEC mode.

 

 

 

• Enter your password if prompted.

 

 

Example:

 

 

 

 

 

 

Router> enable

 

 

 

 

 

Step 2

 

 

 

configure terminal

Enters global configuration mode.

 

 

Example:

 

 

 

 

 

 

Router# configure terminal

 

 

 

 

 

Step 3

 

 

 

ip routing

Enables IP routing.

 

 

Example:

 

 

 

 

 

 

Router(config)# ip routing

 

 

 

 

 

 

 

 

 

 

 

 

 

Cisco 1900 Series Hardware Installation

 

 

 

 

 

 

 

 

 

 

 

 

 

OL-19084-02

 

 

5-15

 

 

 

 

 

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Contents Text Part Number OL-19084-03 Americas HeadquartersPage OL-19084-03 Console and Auxiliary Port Considerations Chassis Airflow Diagram Configuring the Auxiliary Line Audience ObjectivesConventions OrganizationSection Title Description Convention IndicationBewaar Deze Instructies Aviso Instruções Importantes DE Segurança Warnung Wichtige SicherheitshinweiseAvvertenza Importanti Istruzioni Sulla Sicurezza Guarde Estas Instrucciones GEM Disse Anvisninger Xiii Xiv Related Documentation Searching within Cisco Documents Obtaining Documentation and Submitting a Service RequestOverview of the Router Safety WarningsSYS ACT PoE12 Safety Warnings for Finland, Norway and SwedenChassis Views Cisco SYS ACT Antenna mounts1 LEDs2Wlan 4 or 5 GHzOverview of the Router Hardware Features Hardware FeaturesClei Product Serial Number LocationCisco Product Identification Tool Built-In InterfacesProduct ID PID Compliance label CleiInterface Description Removable, Interchangeable, and Optional ModulesUSB Such as security tokens and flash memoryExternal Modules In chassis slots Internal Modules MemorySeries 1905 1921 DramSYS LED IndicatorsColor Description Location ISM/WLAN Chassis Ventilation Wireless LAN ConnectivityReal-Time Clock Chassis SecurityInterface Numbering Baud Reset ButtonSlot Number Slot Type Slot Numbering Range Onboard Ports 10/100/1000 EthernetPower SpecificationsDescription Specification Physical Ports Description SpecificationTransportation and Storage Environment AcousticTIA/EIA/IS-968 CNS ITU-T G.823, G.824 Regulatory ComplianceGeneral Guidelines Safety RecommendationsSafety with Electricity Preventing Electrostatic Discharge Damage General Site RequirementsSite Environment Power Supply ConsiderationsSite Configuration Wireless LAN Considerations Installation ChecklistInspecting the Router Task Verified bySite Log Installation Checklist for Site Router NameTask Verified by Date Router quick start guide receivedCisco 1900 Series Hardware Installation OL-19084-02 OL-19084-02 Console Port Connections Console and Auxiliary Port ConsiderationsAbout Console and Auxiliary Ports USB Console OS Compatibility EIA/TIA-232 PortUSB Serial Console Auxiliary Port Connections Preparing to Connect to a NetworkEthernet Connections Serial ConnectionsSignaling Standards Supported Configuring Serial ConnectionsAbout Serial Connections Serial DTE or DCE DevicesAsynchronous/Synchronous Serial Module Baud Rates Transmission Speeds and Distance LimitationsDistance for EIA/TIA-232 EIA-530 Distance for USB Rate bps Feet MetersCSU/DSU Connections Isdn BRI ConnectionsLow-Capacitance Cable For more information on BRI WICs, refer to Cisco.comAbout Modules Internal services module ISMInternal Modules Router’s internal components include the followingPlug-In Modules Chassis Airflow Diagram Setting Up the ChassisWall-Mounting the Chassis Setting the Chassis on a DesktopChassis Grounding 253711 Wall-Mounting Features on the Cisco 1941 Router ProcedureAttaching Rack-Mount Brackets to Cisco 1900 Series Routers Rack-Mounting the Chassis253712 9shows how to attach the brackets to the rack Installing the Chassis Ground Connection11 Chassis Ground Connection on the Cisco 1941 Router Safety Messages Connecting WAN and LAN CablesOL-19084-02 Port Type, Color Connected to Cable Ports and CablingConnecting to the Console Port with Microsoft Windows Connecting to a Console Terminal or ModemConnection Procedures and Precautions 12 Connecting the Console Cable to the Router Connecting to the Console Port with Linux Connecting to the Console Port with Mac OSOpen the Linux Terminal window Connect the Linux USB port to the routerBefore You Begin Procedure Installing the Cisco Microsoft Windows XP USB DriverInstalling the Cisco Microsoft Windows 2000 USB Driver Installing the Cisco Microsoft Windows Vista USB Driver Uninstalling the Cisco USB DriverUsing the Add Remove Programs Utility Before You BeginUsing the Setup.exe Program Uninstalling the Cisco Microsoft Windows Vista USB Driver13 Connecting a Modem to the Router Connecting to the Auxiliary PortConnecting to AC Power Connecting PowerDC Wiring Requirements for Cisco 1900 Series Routers Connecting to DC PowerWire Size Wire Terminal Lug Protection DC InputCisco 1900 Series Router Wiring Procedure for DC Input 14 DC Power Wire Connection 15 Installing the Plastic Safety Cover OL-19084-02 Checklist Before Powering Up the Cisco Router Powering up the RouterRelated Information Powering Up the Cisco RouterUsing the Cisco Setup Command Facility Performing the Initial Configuration on the Router5-6 to configure the router Verifying the Front Panel LED IndicationsSystem displays a summary of the available interfaces To proceed using the setup command facility, enter yesEnter a hostname for the router System displays the user prompt System creates the following configuration command scriptUsing the Cisco CLI-Manual Configuration Using Cisco Configuration Professional ExpressWhen the system message appears on the router, enter no Initial CLI ConfigurationType enable to enter privileged Exec mode Press Return to bring up the Router promptCommand or Action Purpose Configuring the Router HostnameVerify that the router prompt displays your new hostname ExampleOptional Returns to privileged Exec mode Configuring the Enable and Enable Secret PasswordsConfiguring the Console Idle Privileged Exec Timeout That the privileged Exec command interpreter waits until Command collection modeExample shows how to specify no timeout. Setting Exec-timeout value to 0 will cause the router toLearn which type of Ethernet interface is on your Configuring Gigabit Ethernet InterfacesFor IP Sample Output for the show ip interface brief Command Configuring the GigabitEthernet InterfaceConfiguring IP Routing and IP Protocols Specifying a Default Route or Gateway of Last ResortGateway of Last Resort Routerconfig# ip routingSample Output for the show ip route Command Specifying a Default Route ExampleVirtual terminal lines vty for remote console access Starts the line configuration command collection mode forMake sure that you configure all vty lines on your Line vty ? commandExample Configuring the Auxiliary LineAuxiliary line Verifying Network ConnectivityIf you want to test the vty line password, perform this Connected host for each configured interfaceDiagnoses initial network connectivity To verify connectivity, ping the next hop router orSaving Backup Copies of Configuration and System Image Saving Your Router ConfigurationSaves the running configuration to the startup ConfigurationCopying from Flash Memory to a Tftp Server Example Copying the Startup Configuration to a Tftp Server ExampleNvram Verifying the Initial ConfigurationOL-19084-02 Getting Software Licenses for the Router Activating a New Software Package or Feature1shows the steps for software activation RMA License TransferAdditional Information OL-19084-02
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