Connecting an EX Series Switch to a Modem

You can connect an EX Series switch to a modem through the console port on the switch.

Before you connect the port to the modem, you must set the serial console speed on the switch and configure port settings on the modem.

Before you connect the switch to a modem:

Ensure that you have the following parts available before you begin to connect the switch to the modem:

This topic describes:

  1. Setting the Serial Console Speed for the Switch
  2. Configuring the Modem
  3. Connecting the Modem to the Console Port

Setting the Serial Console Speed for the Switch

Before you can connect the switch to a modem, the switch’s serial console speed must be set to 115200 baud.

Note: The default serial console speed is 9600 baud.

To change the serial console speed:

  1. Power on the switch. (If the switch is an EX8208 or EX8216 model, see Powering On an EX8200 Switch.) The loader script starts.
  2. You are prompted with:

    Hit [Enter] to boot immediately, or space bar for command prompt.

    Press the Spacebar to pause the switch in the loader state (after the JUNOS Software has loaded on the switch but before the software starts).

    The loader> prompt appears.

  3. Set the baud rate:

    loader> set baudrate=115200

    Press Enter.

  4. Press Enter when you see the following message:

    Switch baud rate to 115200 bps and press Enter.

    The loader> prompt reappears.

  5. Save the new serial console speed:

    loader> save

    Press Enter. The serial console speed is now set to 115200 baud.

  6. Boot the software:

    loader> boot

    The boot process proceeds as normal and ends with a login prompt.

Configuring the Modem

Before you connect the modem, you must configure the modem with required port settings.

Note: The following procedure uses Hayes-compatible-modem commands to configure the modem. If your modem is not Hayes-compatible, see the documentation for your modem for the equivalent modem commands.

To configure the modem:

  1. Connect the modem to the desktop or notebook computer.
  2. Power on the modem.
  3. From the computer, start your asynchronous terminal emulation application (such as Microsoft Windows HyperTerminal) and select the COM port to which the modem is connected (for example, COM1).
  4. Configure the port settings shown in Table 22.

    Table 22: Port Settings

    Port Settings

    Value

    Bits per second

    115200

    Data bits

    8

    Parity

    None

    Stop bits

    1

    Flow control

    None

  5. In the HyperTerminal window, type at. Press Enter.

    The modem sends an OK response to verify that it can communicate successfully with the COM port on your desktop or notebook computer.

  6. To configure the modem to answer a call on the first ring, type ats0=1 at the prompt. Press Enter.
  7. To configure the modem to accept modem-control DTR signals, type at&d1 at the prompt. Press Enter.
  8. To disable flow control on the modem, type at&k0 at the prompt. Press Enter.
  9. To set the fixed serial port speed on the modem, type at&b1 at the prompt. Press Enter.

    Note: You must set the serial port to the fixed speed so that the modem will not adjust the serial port speed to the negotiated line speed.

  10. To save the new modem settings, type at&w0 at the prompt. Press Enter.

    The modem sends an OK message. The modem is now ready to be connected to the switch.

Connecting the Modem to the Console Port

The console port on every EX Series switch accepts a cable with an RJ-45 connector. Figure 33 shows the RJ-45 connector of the Ethernet cable supplied with the switch.

Figure 33: Ethernet Cable Connector

Image g001063.gif

Note: If your laptop or PC does not have a DB-9 male connector pin and you want to connect your laptop or PC directly to the switch, use a combination of the RJ-45 to DB-9 female adapter supplied with the switch and a USB to DB-9 male adapter. You must provide the USB to DB-9 male adapter.

Note: Most modems have an RS-232 DB-25 connector. You must separately purchase an adapter to connect your modem to the RJ-45 to DB-9 adapter and Ethernet cable supplied with the switch.

To connect a modem to the console port:

  1. Turn off power to the switch.
  2. Turn off power to the modem.
  3. Connect one end of the cable to the console port (labeled CON or CONSOLE) on the switch.

    For the location of the console port on different EX Series switches:

  4. Connect the other end of the cable to the RJ-45 to DB-9 serial port adapter supplied with your switch.
  5. Connect the serial port adapter to the DB-9 female to DB-25 male adapter or other adapter appropriate for your modem.
  6. Plug the modem adapter into the DB-25 connector on the modem.
  7. Connect one end of the phone cable to the modem and the other end to your telephone network.
  8. Turn on the power to your modem.
  9. Power on the switch.

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