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How To Find the PCI Address of an Ethernet Interface in Ubuntu

Ubuntu 21

In this article, we will be discussing how to find the PCI (Peripheral Component Interconnect) address of an Ethernet interface in Ubuntu. This information can be useful for system administrators and network engineers when troubleshooting network issues or configuring network devices.

What is a PCI Address?

A PCI address is a unique identifier assigned to each device connected to the PCI bus in a computer. This address is used by the operating system to communicate with the device. In the context of an Ethernet interface, the PCI address can help you identify the specific network card that the operating system is using.

Method 1: Using lshw

The lshw command is a powerful tool that provides detailed information about all the hardware components in your system. To use it to find the PCI address of an Ethernet interface, follow these steps:

  1. Open a terminal window.
  2. Type the following command and press Enter:
sudo lshw -c network -businfo

This command displays the bus information (-businfo) for all network devices (-c network). The output will look something like this:

Bus info Device Class Description
=====================================================
pci@0000:0e:00.0 wlan0 network RTL8187SE Wireless LAN Controller
pci@0000:14:00.0 eth0 network RTL8101E/RTL8102E PCI Express Fast Ethernet controller

In this example, the PCI address for eth0 (the Ethernet interface) is 0000:14:00.0.

Method 2: Using lspci

The lspci command lists all PCI devices. To use it to find the PCI address of an Ethernet interface, follow these steps:

  1. Open a terminal window.
  2. Type the following command and press Enter:
lspci -D | grep 'Network\|Ethernet'

This command lists all PCI devices in a machine-readable format (-D), then filters the output to show only lines containing the words ‘Network’ or ‘Ethernet’ (grep 'Network\|Ethernet'). The output will look something like this:

0000:0e:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8187SE Wireless LAN Controller (rev 22)
0000:14:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02)

In this example, the PCI address for the Ethernet controller is 0000:14:00.0.

Method 3: Using sysfs

The sysfs filesystem provides a way to access kernel object information from user space. To use it to find the PCI address of an Ethernet interface, follow these steps:

  1. Open a terminal window.
  2. Type the following command and press Enter:
grep PCI_SLOT_NAME /sys/class/net/*/device/uevent

This command searches for the string ‘PCI_SLOT_NAME’ in the uevent files of all network devices (/sys/class/net/*/device/uevent). The output will look something like this:

/sys/class/net/enp4s0/device/uevent:PCI_SLOT_NAME=0000:04:00.0
/sys/class/net/wlp2s0/device/uevent:PCI_SLOT_NAME=0000:02:00.0

In this example, the PCI address for enp4s0 (the Ethernet interface) is 0000:04:00.0.

Method 4: Using ethtool

The ethtool utility is used to display and change the settings of network devices. To use it to find the PCI address of an Ethernet interface, follow these steps:

  1. Open a terminal window.
  2. Type the following command and press Enter:
ethtool -i eth0

This command displays information about eth0 (-i eth0). The output will look something like this:

driver: i40e
version: 1.5.16
firmware-version: 5.04 0x800024cd 0.0.0
bus-info: 0000:06:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes

In this example, the PCI address for eth0 is 0000:06:00.0.

Conclusion

In this article, we have discussed four different methods to find the PCI address of an Ethernet interface in Ubuntu. Depending on your specific needs and the tools available on your system, you may choose to use one method over the others. Regardless of the method used, the goal is the same: to identify the PCI address of the Ethernet interface for troubleshooting or configuration purposes.

What is the purpose of finding the PCI address of an Ethernet interface in Ubuntu?

Finding the PCI address of an Ethernet interface in Ubuntu can be useful for system administrators and network engineers when troubleshooting network issues or configuring network devices. It helps identify the specific network card that the operating system is using.

How do I use the `lshw` command to find the PCI address of an Ethernet interface?

To use the lshw command, open a terminal window and type sudo lshw -c network -businfo. This command will display the bus information for all network devices. Look for the line that corresponds to the Ethernet interface, and the PCI address will be listed in the "Bus info" column.

How do I use the `lspci` command to find the PCI address of an Ethernet interface?

To use the lspci command, open a terminal window and type lspci -D | grep 'Network\|Ethernet'. This command lists all PCI devices and filters the output to show only lines containing the words ‘Network’ or ‘Ethernet’. The PCI address of the Ethernet interface will be listed at the beginning of each line.

How do I use sysfs to find the PCI address of an Ethernet interface?

To use sysfs, open a terminal window and type grep PCI_SLOT_NAME /sys/class/net/*/device/uevent. This command searches for the string ‘PCI_SLOT_NAME’ in the uevent files of all network devices. The PCI address of each Ethernet interface will be listed next to the corresponding device.

How do I use the `ethtool` command to find the PCI address of an Ethernet interface?

To use the ethtool command, open a terminal window and type ethtool -i eth0. This command displays information about the Ethernet interface specified after the -i flag. Look for the line starting with "bus-info:" in the output, and the PCI address will be listed after that.

Which method should I use to find the PCI address of an Ethernet interface?

The method you choose depends on your specific needs and the tools available on your system. All four methods (using lshw, lspci, sysfs, and ethtool) can provide the PCI address of an Ethernet interface. Choose the method that you are most comfortable with or that suits your troubleshooting or configuration requirements.

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