{"id":26813,"date":"2024-08-21T15:34:04","date_gmt":"2024-08-21T12:34:04","guid":{"rendered":"https:\/\/wifilab.org\/2024\/08\/21\/basic-configuration-of-a-cisco-router-for-internet-connectivity\/"},"modified":"2024-10-21T19:06:29","modified_gmt":"2024-10-21T16:06:29","slug":"basic-configuration-of-a-cisco-router-for-internet-connectivity","status":"publish","type":"post","link":"https:\/\/wifilab.org\/en\/2024\/08\/21\/basic-configuration-of-a-cisco-router-for-internet-connectivity\/","title":{"rendered":"Basic configuration of a Cisco router for Internet connectivity."},"content":{"rendered":"\t\t
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Configuring Cisco from the specialists of WiFiLab is always professional and high quality!<\/span><\/h3>\n

Cisco Setup: Connecting your office to the Internet<\/strong><\/p>\n

This article details the process of configuring a Cisco 881 router to connect your office network to the Internet. Note that the configuration commands for other Cisco router models, such as the 1841, 2800, and 3825, will be similar, although there may be differences in interface names and numbering. <\/p>\n

Wiring diagram description<\/h3>\n

Present in our scheme are:<\/p>\n

    \n
  • Channel to the Internet using a static IP address<\/li>\n
  • Multiple computers on the office LAN<\/li>\n
  • Cisco router<\/li>\n
  • Switch for organizing a local area network<\/li>\n<\/ul>\n

    The main task is to provide access of local network computers to the Internet.<\/p>\n

    Step 0: Clear the router configuration <\/h3>\n

    The first thing to do before you start configuring your Cisco router is to clear the startup configuration of the device. To do this, connect to the console port of the router using a special cable and execute the following commands: <\/p>\n

      \n
    1. \n

      Log in to privileged mode (you may need to enter a username and password):<\/p>\n

      \n
      router> <\/span>enable<\/span><\/span>
      \n<\/code><\/div>\n<\/div>\n<\/li>\n
    2. \n

      Delete the startup configuration:<\/p>\n

      \n
      router# write erase<\/span>
      \n<\/code><\/div>\n<\/div>\n<\/li>\n
    3. \n

      Confirm the deletion and reboot the router:<\/p>\n

      \n
      router# reload<\/span>
      \n<\/code><\/div>\n<\/div>\n<\/li>\n<\/ol>\n

      After rebooting, the router will prompt you to start basic setup. Refuse to do so: <\/p>\n

      \n
      Would you like to enter the basic configuration dialog (yes<\/span>\/no): no
      \n<\/code><\/div>\n<\/div>\n

      Now only the standard default strings will remain in the router configuration, and you can move on to the main configuration.<\/p>\n

      Step 1: Configuring the device name <\/h3>\n

      Set the router name for ease of administration:<\/p>\n

      \n
      router# conf t<\/span>
      \nrouter<\/span> (config)# hostname R-DELTACONFIG<\/span>
      \nR-DELTACONFIG<\/span>(config)#
      \n<\/code><\/div>\n<\/div>\n

      Step 2: Configuring the interfaces <\/h3>\n

      Two interfaces need to be configured: an external interface for communication with the Internet and an internal interface for the local network. The external interface will receive IP addresses and mask provided by the ISP, and the internal interface will be configured for the 192.168.0.0\/24 network. <\/p>\n

      Suppose a service provider has provided the following addresses:<\/p>\n

        \n
      • Network: 200.150.100.0<\/li>\n
      • Subnet mask: 255.255.255.255.252 (\/30)<\/li>\n
      • Default gateway: 200.150.100.1<\/li>\n<\/ul>\n

        Configuring the external interface:<\/p>\n

        \n
        R-DELTACONFIG# conf t<\/span>
        \nR-DELTACONFIG<\/span> (config)# interface Fa 4<\/span>
        \nR-DELTACONFIG<\/span> (config-if<\/span>)# ip address 200.150.100.2 255.255.255.252<\/span>
        \nR-DELTACONFIG<\/span> (config-if<\/span>)# no shutdown<\/span>
        \n<\/code><\/div>\n<\/div>\n

        Connect this router interface to the ISP equipment and check its availability using the command ping<\/code>:<\/p>\n

          \n
        1. \n

          First, check your own interface:<\/p>\n

          \n
          R-DELTACONFIG# ping 200.150.100.2<\/span>
          \n<\/code><\/div>\n<\/div>\n<\/li>\n
        2. \n

          Then check the access to the ISP gateway:<\/p>\n

          \n
          R-DELTACONFIG# ping 200.150.100.1<\/span>
          \n<\/code><\/div>\n<\/div>\n<\/li>\n<\/ol>\n

          After ensuring that the gateway is available, proceed to configure the internal interface.<\/p>\n

          The following addressing will be used on the LAN:<\/p>\n

            \n
          • Network: 192.168.0.0<\/li>\n
          • Subnet mask: 255.255.255.255.0<\/li>\n
          • The internal address of the router (gateway): 192.168.0.1<\/li>\n<\/ul>\n

            To configure the internal interface, use the command to enter Vlan 1 virtual interface configuration mode:<\/p>\n

            \n
            R-DELTACONFIG# conf t<\/span>
            \nR-DELTACONFIG<\/span> (config)# interface Vlan 1<\/span>
            \nR-DELTACONFIG<\/span> (config-if<\/span>)# ip address 192.168.0.1 255.255.255.0<\/span>
            \nR-DELTACONFIG<\/span> (config-if<\/span>)# no shutdown<\/span>
            \n<\/code><\/div>\n<\/div>\n

            Then bind the virtual interface to the physical interface:<\/p>\n

            \n
            R-DELTACONFIG<\/span> (config)# interface Fa 0<\/span>
            \nR-DELTACONFIG<\/span> (config-if<\/span>)# switchport access vlan 1<\/span>
            \nR-DELTACONFIG<\/span> (config-if<\/span>)# no shutdown<\/span>
            \n<\/code><\/div>\n<\/div>\n

            Now connect the Fa 0 interface to the switch to which the workstations are connected and check the availability of the router interface using the command ping<\/code>.<\/p>\n

            Step 3: Configuring Remote Access to the Router <\/h3>\n

            You can use Telnet or SSH protocols to remotely access the router console. Let’s consider configuring a secure connection via SSH: <\/p>\n

              \n
            1. \n

              Enable SSH version 2 and set the domain name:<\/p>\n

              \n
              R-DELTACONFIG<\/span> (config)# ip ssh version 2<\/span>
              \nR-DELTACONFIG<\/span> (config)# ip domain-name xxx.ru<\/span>
              \n<\/code><\/div>\n<\/div>\n<\/li>\n
            2. \n

              Generate RSA keys:<\/p>\n

              \n
              R-DELTACONFIG<\/span> (config)# crypto key generate rsa<\/span>
              \nHow many bits in the modulus [512<\/span>]: 1024<\/span>
              \n<\/code><\/div>\n<\/div>\n<\/li>\n
            3. \n

              Set the user name and password:<\/p>\n

              \n
              R-DELTACONFIG<\/span> (config)# username admin privilege 15 secret 0 *****<\/span>
              \n<\/code><\/div>\n<\/div>\n<\/li>\n
            4. \n

              Enable authorization through the local base:<\/p>\n

              \n
              R-DELTACONFIG<\/span> (config)# line<\/span> vty 0 4<\/span>
              \nR-DELTACONFIG<\/span> (config-line)# login local<\/span>
              \n<\/code><\/div>\n<\/div>\n<\/li>\n
            5. \n

              Set the password to privileged mode:<\/p>\n

              \n
              R-DELTACONFIG<\/span> (config-line)# enable secret 0 *****<\/span>
              \n<\/code><\/div>\n<\/div>\n<\/li>\n<\/ol>\n

              You can now remotely connect to the router using a program that supports SSH.<\/p>\n

              Step 4: Configure the default gateway <\/h3>\n

              Specify a default gateway to route packets to the Internet:<\/p>\n

              \n
              \n
              \n