This knowledge base has moved to the documentation site. Please visit the knowledge base here for the most up to date content. This site is no longer maintained.

Error seen: portwd invalid SFF identifier



The following log messages constantly appear in /var/log/syslog:

2017-03-16T00:39:30.292349+00:00 hostname portwd: Port 49, invalid SFF identifier: 0x0c
2017-03-16T00:39:30.298340+00:00 hostname portwd: Port 50, invalid SFF identifier: 0x0c
2017-03-16T00:39:30.300035+00:00 hostname portwd: Port 50, invalid SFF identifier: 0x0c
2017-03-16T00:39:30.301740+00:00 hostname portwd: Port 50, invalid SFF identifier: 0x0c
2017-03-16T00:39:30.303486+00:00 hostname portwd: Port 50, invalid SFF identifier: 0x0c
2017-03-16T00:39:30.309608+00:00 hostname portwd: Port 51, invalid SFF identifier: 0x0c


  • Cumulus Linux 3.y.z


This issue occurs because portwd is unable to correctly identify the optic. This is usually because the optic has not correctly identified its capabilities.

Here is an example of ethtool output showing a correctly identified optic:

cumulus@switch:~$ sudo ethtool -m swp1
        Identifier                                : 0x0d (QSFP+)
        Extended identifier                       : 0x00 (1.5W max. Power consumption, No CDR in TX, No CDR in RX)
        Connector                                 : 0x0c (MPO Parallel Optic)
        Transceiver codes                         : 0x04 0x00 0x00 0x00 0x40 0x40 0x02 0x00
        Transceiver type                          : 40G Ethernet: 40G Base-SR4
        Transceiver type                          : FC: short distance (S)
        Transceiver type                          : FC: Shortwave laser w/o OFC (SN)
        Transceiver type                          : FC: Multimode, 50um (OM3)

Here is an example of ethtool output showing an optic that has not identified its capabilities:

cumulus@switch:~$ sudo ethtool -m swp29
        Identifier                                : 0x0d (QSFP+)
        Extended identifier                       : 0xdc (3.5W max. Power consumption, CDR present in TX, CDR present in RX)
        Connector                                 : 0x07 (LC)
        Transceiver codes                         : 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
        Encoding                                  : 0x05 (64B/66B)


If you encounter this message and believe the optic is not behaving as expected, then open a case with the Cumulus Networks Support team.

Suppressing Log Messages

The "Invalid SFF Identifer" log message will generate constantly in your /var/log/syslog, making it harder to interpret other log messages. You can prevent the logging of this message by adding the following line to your rsyslog configuration:

:msg, contains, "invalid SFF identifier:" ~

This configuration needs to be added before the /var/log/syslog file is defined. The simplest way to do this is to create a file named /etc/rsyslogd.d/1-suppress.conf and put the entry in this file:

  1. Create the file:
    cumulus@switch:~$ sudo vi /etc/rsyslog.d/1-suppress.conf
  2. Add the following line to the file:
    :msg, contains, "invalid SFF identifier:" ~
  3. Restart rsyslogd:
    cumulus@switch:~$ sudo systemctl restart rsyslog.service


This support portal has moved

Cumulus Networks is now part of the NVIDIA Networking Business Unit! The NVIDIA Cumulus Global Support Services (GSS) team has merged its operations with the NVIDIA Mellanox support services team.

You can access NVIDIA Cumulus support content from the Mellanox support portal.

You open and update new cases on the Mellanox support portal. Any previous cases that have been closed have been migrated to the Mellanox support portal.

Cases that are still open on the Cumulus portal will continue to be managed on the Cumulus portal. Once these cases close, they will be moved to the Mellanox support portal.

Powered by Zendesk