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Cisco Bug: CSCuo39308 - An LLDP frame with length of 0 in an optional TLV is discarded

Last Modified

May 08, 2020

Products (8)

  • Cisco Nexus 7000 Series Switches
  • Cisco Nexus 7000 10-Slot Switch
  • Cisco Nexus 7000 4-Slot Switch
  • Cisco Nexus 7700 6-Slot Switch
  • Cisco Nexus 7700 18-Slot Switch
  • Cisco Nexus 7000 18-Slot Switch
  • Cisco Nexus 7000 9-Slot Switch
  • Cisco Nexus 7700 10-Slot Switch

Known Affected Releases


Description (partial)

The following syslog message is seen on an NX-OS device:

2014 Apr  1 16:31:13.550 N7K_1 LLDP-3-INVALID_LLDP_RECEIVED Received an invalid LLDP on Eth4/31

1.This bug will be seen in N7K 6.2.8 and all the N7K releases before that
2.This bug has been resolved and will not be seen in 6.2.10 and onwards.

An LLDP peer of an NXOS device is including an optional TLV in the LLDP frame with a length of 0.  This particular optional TLV does not have a specified minimum length per the LLDP standard (802.1AB)

Also, the logging level for lldp has been increased from its default of '2' to 3 or higher:

N7K_1# show logging level lldp
Facility        Default Severity        Current Session Severity
--------        ----------------        ------------------------
lldp                    2                       5 <<<<<<<<<<<<<<<<<<<<<<<

0(emergencies)          1(alerts)       2(critical)
3(errors)               4(warnings)     5(notifications)
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