Physical Ports Missing from ip link show Output - switchd Failure


ip link show displays only the loopback and management (ethX) ports. Physical switch ports — the interfaces starting with swp — are not visible to the operating system.

$ sudo ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN mode DEFAULT 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
    link/ether 44:38:39:00:25:d7 brd ff:ff:ff:ff:ff:ff


  • Cumulus Linux, all versions


The switchd daemon sets up the physical ports. When switchd fails to start, the physical ports are not visible to the operating system.


Typically, switchd fails to start when the Cumulus Linux license is missing.

If you installed your license and switchd still fails to start, capture any errors that might occur and generate the cl-support files, then send them to the NVIDIA support team.

Follow the appropriate steps below.

If the Cumulus Linux License Is not Installed

If you do not install a valid license, the physical ports cannot come up. Verify that you installed the license using the cl-license command.

$ sudo cl-license
No license installed!

Contact the NVIDIA support team to obtain a license.

switchd Fails to Start with the Error: Syntax error parsing “thdi_input_port_xon_enables.xe0-xe127”

This error occurs when the port capacity configured on the switch exceeds the capability of the ASIC. Read the heading in the /etc/cumulus/ports.conf file for details on how to configure the ports.conf file. If the header is missing, run the cl-img-clear-overlay command to restore the switch back to its original configuration. Make sure to remove the /mnt/persist/etc/cumulus/ports.conf file if it exists.

Error: “No attached units. BDE found 0 switch devices.”

An error like this indicates the kernel cannot find the Broadcom ASIC. After you manually start the switchd service using the service switchd start command, check the /var/log/switchd.log for the following error:

Platform: Cumulus_Networks_LLC
OS: Unix (Posix)
Boot flags: Cold boot
No attached units.
BDE found 0 switch device(s)
1421276331.445789 2014-01-11 10:33:51 hal.c:169 CRIT No backends found.
1421276331.445857 2014-01-11 10:33:51 switchd.c:632 Switchd exiting.

If you see the above error, confirm that the Broadcom ASIC is not seen by the kernel by running the lspci -v command. Look for the following output:

01:00.0 Ethernet controller: Broadcom Corporation Device b850 (rev 03) 
Subsystem: Broadcom Corporation Device b850 
Flags: bus master, fast devsel, latency 0, IRQ 21 
Memory at ff600000 (64-bit, non-prefetchable) [size=256K] 
Capabilities: [48] Power Management version 3 
Capabilities: [50] Vital Product Data 
Capabilities: [58] MSI: Enable- Count=1/1 Maskable- 64bit+ 
Capabilities: [ac] Express Endpoint, MSI 00 
Kernel driver in use: linux-kernel-bde

If the above output is missing, replace the switch.

If switchd Fails to Start for Another Reason

Manually start the switchd service using the service switchd start command. You must have root/sudo access.

$ sudo service switchd restart

can not execute decode-syseeprom
.py", line 544, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '('/usr/cumulus/bin/decode-syseeprom', '-r')' returned non-zero exit status 1
-m requires a MAC address as an argument
usage: /usr/sbin/switchd [-n] [-d] [-V] [-L BACKEND=LEVEL [BACKEND=LEVEL]] [-t TABLE_NUM] [-s]

If an error occurs:

  1. Save the entire error message.
  2. Download any Cumulus Linux support files. The support files are located in /var/support/core.
  3. Open a case with Cumulus Support and upload the above information.