Pin 8<\/strong><\/td>\n| CTS (Clear to Send)<\/td>\n | Input to Router<\/td>\n | Pin 7 (RTS)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n When connecting an RJ-45 rollover cable to a legacy DB-9 serial port, a modular DB-9 to RJ-45 female adapter (Cisco part number 74-0495-01) aligns the inverted signals with the terminal’s serial controller.<\/p>\n <\/span>USB Console Ports<\/span><\/h3>\nCisco routers equipped with USB Mini-B or USB Type-C console interfaces incorporate an internal USB-to-UART bridge. These interfaces function as USB 2.0 full-speed slave devices. When both the RJ-45 and USB console ports are present on a single chassis, connecting the USB cable typically takes precedence by default, disabling the RJ-45 port until the USB connection is disconnected or administratively redirected.<\/p>\n
\nWith the physical interface architecture established, modern workstations must bridge the gap between their USB ports and the router’s serial bus by deploying virtual communications port drivers.<\/p>\n <\/span>Installing USB Console Cable and Virtual COM Port Drivers<\/span><\/h2>\nBecause modern laptops and desktop computers do not feature native RS-232 DB-9 serial ports, administrators utilize either an integrated USB-to-RJ45 rollover cable or a standard USB cable connected to the router’s USB Mini-B\/Type-C port. In both instances, the operating system requires Virtual COM Port (VCP) drivers to map the serial bridge into software.<\/p>\n <\/span>Step 1: Identify the Hardware Chipset<\/span><\/h3>\nCheck the specifications of your console cable:
\n* Third-Party USB-to-RJ45 Cables:<\/strong> Predominantly powered by an FTDI FT232R or a Prolific PL2303 chipset embedded within the USB housing.
\n* Direct USB Console Ports:<\/strong> Utilize Cisco’s proprietary USB-to-UART hardware embedded directly on the router’s motherboard.<\/p>\n<\/span>Step 2: Download Verified Driver Packages<\/span><\/h3>\nObtain the appropriate driver directly from the hardware vendor:
\n* FTDI Chipsets:<\/strong> Navigate to the FTDI Chip official website and download the VCP driver executable installer tailored for your operating system architecture.
\n* Prolific Chipsets:<\/strong> Obtain the authenticated PL2303 VCP driver installer from Prolific Technology.
\n* Native Cisco USB Ports:<\/strong> Sign in to Cisco Software Central, browse to your specific router platform (such as the ISR 4000 or Catalyst 8300 series), open the Routers<\/strong> software category, and download the official Cisco USB Console Windows Driver<\/strong> (typically distributed as an executable such as Cisco_USB_Console_Driver_3_1.exe<\/code>).<\/p>\n<\/span>Step 3: Execute Driver Installation<\/span><\/h3>\nRun the downloaded installer with administrative privileges prior to plugging in the cable. Installing beforehand stages the driver binaries (.inf<\/code> and .sys<\/code> files) directly into the Windows Driver Store (C:\\Windows\\System32\\DriverStore<\/code>), preventing operating system conflicts or incorrect generic driver bindings.<\/p>\n<\/span>Step 4: Verify COM Port Enumeration<\/span><\/h3>\n\n- Plug the USB console cable into an available USB port on your workstation.<\/li>\n
- Press Windows Key + X<\/strong> and select Device Manager<\/strong>.<\/li>\n
- Expand the Ports (COM & LPT)<\/strong> branch.<\/li>\n
- Confirm that your device is listed cleanly without a yellow warning icon, appearing as USB Serial Port (COMx)<\/strong> or Cisco USB Console Port (COMx)<\/strong>.<\/li>\n
- Record the designated COM number (e.g.,
COM3<\/code>), as this parameter is required by your terminal emulator.<\/li>\n<\/ol>\n
\nAfter the operating system assigns a valid communications port, your terminal software must be configured with Cisco’s standardized serial interface parameters to establish readable communications.<\/p>\n <\/span>Frequently Asked Questions: Default Serial Settings and COM Port Parameters<\/span><\/h2>\n<\/span>What are the default serial settings for a Cisco router console port?<\/span><\/h3>\nCisco routers use a standardized serial communications profile across almost all hardware families:
\n* Baud Rate (Speed):<\/strong> 9600 bps
\n* Data Bits:<\/strong> 8
\n* Parity:<\/strong> None
\n* Stop Bits:<\/strong> 1
\n* Flow Control:<\/strong> None<\/p>\nIn networking documentation, this configuration is abbreviated as 9600 8-N-1<\/strong>.<\/p>\n<\/span>Why must Flow Control be set to “None”?<\/span><\/h3>\nFlow control manages data flow rates between two serial endpoints. In RS-232, this is achieved either via software signaling (XON\/XOFF) or hardware handshaking lines (RTS\/CTS). Cisco console ports default to flow control disabled. If your terminal software defaults to RTS\/CTS hardware flow control, and your serial cable lacks connected handshaking pins, the terminal client waits indefinitely for a clear-to-send signal, freezing all keyboard input and terminal display updates.<\/p>\n <\/span>Which terminal emulation mode should be selected?<\/span><\/h3>\nYou should select VT100<\/strong> or ANSI<\/strong> emulation. Cisco IOS and IOS XE formatting engines rely on standardized VT100 escape sequences to execute cursor positioning, render line wrapping, and handle interactive CLI pagers such as the --More--<\/code> prompt.<\/p>\n<\/span>Can the default baud rate be customized?<\/span><\/h3>\nYes. Administrators can adjust line speeds using the speed <baud><\/code> command within line con 0<\/code> configuration mode, or via configuration register modifications in ROMmon. However, until custom configurations are actively applied during boot, 9600 baud remains the baseline factory fallback.<\/p>\n
\nApplying these standard serial parameters on a Windows machine is most commonly achieved using PuTTY, an industry-standard open-source terminal client.<\/p>\n <\/span>Connecting to a Cisco Console Port via PuTTY on Windows<\/span><\/h2>\nPuTTY provides raw serial client support, allowing direct transmission across virtual COM ports without protocol overhead.<\/p>\n <\/span>Step 1: Connect Physical Cabling<\/span><\/h3>\nPlug the RJ-45 connector of your rollover cable into the router port labeled CONSOLE<\/strong> (demarcated by light blue trim on Cisco chassis), or insert a USB cable into the corresponding Mini-B or Type-C console slot. Connect the opposite end to your workstation’s USB port.<\/p>\n<\/span>Step 2: Confirm Port Assignment in Windows<\/span><\/h3>\nVerify your assigned port via Windows Device Manager under Ports (COM & LPT)<\/strong>. For this walkthrough, assume the cable is recognized as COM3<\/strong>.<\/p>\n<\/span>Step 3: Configure Connection Settings in PuTTY<\/span><\/h3>\n\n- Launch PuTTY to open the Session<\/strong> configuration screen.<\/li>\n
- In the Connection type<\/strong> selector, choose the Serial<\/strong> radio button.<\/li>\n
- In the Serial line<\/strong> input box, overwrite the default entry with your assigned port (e.g.,
COM3<\/code>).<\/li>\n- In the Speed<\/strong> field, verify the value is set to
9600<\/code>.<\/li>\n<\/ol>\nConnection type: [x] Serial\nSerial line: COM3\nSpeed: 9600\n<\/code><\/pre>\n<\/span>Step 4: Verify Advanced Serial Parameters<\/span><\/h3>\nIn the left-hand navigation tree, navigate to Connection<\/strong> > Serial<\/strong>:
\n* Confirm Data bits<\/strong> is set to 8<\/code>.
\n* Confirm Stop bits<\/strong> is set to 1<\/code>.
\n* Confirm Parity<\/strong> is set to None<\/code>.
\n* Confirm Flow control<\/strong> is set to None<\/code>.<\/p>\n<\/span>Step 5: Save Session Profile and Open Connection<\/span><\/h3>\n\n- Click Session<\/strong> in the left-hand menu.<\/li>\n
- Under Saved Sessions<\/strong>, enter a descriptive label (such as
Cisco-Console-COM3<\/code>).<\/li>\n- Click Save<\/strong> to store this hardware profile for future use.<\/li>\n
- Click the Open<\/strong> button at the bottom of the window.<\/li>\n
- A blank terminal window will appear. Press the Enter<\/strong> key once or twice to awaken the serial buffer. The router will respond with either the initial setup dialog or the standard CLI prompt:<\/li>\n<\/ol>\n
Router>\n<\/code><\/pre>\n
\nWhile Windows requires third-party terminal clients like PuTTY, macOS provides direct console access through its built-in Terminal application without installing external software.<\/p>\n <\/span>Accessing the Cisco Console from macOS Using Terminal<\/span><\/h2>\nModern releases of macOS include built-in kernel support for FTDI, Silicon Labs, and standard CDC-ACM USB-to-serial chips, eliminating manual driver installations for most common console cables.<\/p>\n <\/span>Step 1: Attach Console Hardware<\/span><\/h3>\nConnect your USB console cable to an available USB or Thunderbolt port on your Mac.<\/p>\n <\/span>Step 2: Locate the Serial Device Identifier<\/span><\/h3>\nOpen the macOS Terminal application (press Command + Space<\/strong>, enter Terminal<\/code>, and hit
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