How to Upgrade Firmware of a Switch via the Bootutil Menu

Bootutil is safe mode of a switch. When the switch can’t be launched due to something wrong with the firmware, we can try to login to the bootutil menu and download the firmware to the switch again via FTP function.

Note: this article is only suitable for TP-Link 3 & 5 series (like TL-SG5428E), T2700 and T3700 switches and the bootutil may has some differences in different switches.

1. Hardware Installation

1. Connect the PC to the Console port of the switch.
2. Connect FTP server to port 1 of the switch.
3. Save the firmware (bin file) of the switch in the shared file of FTP server. We assume you have already set up the FTP Server and saved the firmware as below:

• FTP IP address: 192.168.1.4
• FTP user name: admin
• FTP password: 666666
• Firmware name: update.bin

Note: you can refer to FAQ 993 to set up a FTP server.

2. Configure the serial terminal in the PC.

There are many tools can act as serial terminal, here we use PuTTY as example. Please take the following steps to configure the PuTTY to manage the switch.

1. Open the PuTTY.
2. The PuTTY Configuration Window will prompt shown as below, please click Connection—Serial in the left bar and choose the Serial line to connect to, here is COM1 and it is related to the serial port you use, so please choose it according to your real situation. Configure Speed (baud) as 38400, Data bits as 8, Stop bits as 1, Parity as None, Flow control as None.

3. Then please click Session in the left bar and choose Serial and then click Open.

3. Download firmware via bootutil menu

To download firmware to the switch via FTP function, you need to enter into the bootutil menu of the switch and here we take T2700G-28TQ as example.

1. Power off and restart the switch. When you are prompted that “Press CTRL-B to enter the bootutil” in the terminal, please press CTRL-B key to enter into bootutil menu shown as below.

As the prompt is displayed for a short time, you are suggested not to release the CTRL-B key until you enter into bootutil menu after powering on the switch.

2. After entering into bootutil menu, please firstly configure the IP parameters of the switch and the IP address of the switch should be in the same subnet of the FTP Server. Enter 6 and specify the IP address, IP mask and gateway in turn.

For example: Configure the IP address as 192.168.1.100, mask as 255.255.255.0 and gateway as 192.168.1.1. The detailed steps are shown as the figure below.

3. Enter 10 and then choose 1 to configure the parameters of the FTP server which keeps the firmware, and download the firmware to the switch from the FTP server.

4. After download the firmware to the switch successfully, we need to specify the attribute of the downloaded firmware, it is advised to specify it as Backup Image as shown in the picture below.

Note: only the switches with Dual Image function like T2700 and T3700 need this step.

5. Enter 1 and Y to reboot the switch.