Operational Defect Database
BugZero found this defect 55 days ago.
Data sources
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Hewlett Packard Enterprise | a00138524en_us
Advisory: HPE Virtual Connect Modules for Synergy - MAC Address Out-of-Sync Issue May Occur When an External Ethernet Switch Is Incorrectly Configured
Last update date:
3/26/2024
Affected products:
HPE Virtual Connect SE 100Gb F32 Module for Synergy
HPE Virtual Connect SE 40Gb F8 Module for Synergy
Affected releases:
No affected releases provided.
Fixed releases:
No fixed releases provided.
Description:
Info
For any HPE Virtual Connect modules for Synergy listed in the Scope section below, a MAC address out-of-sync issue may occur when an external ethernet switch incorrectly reflects one (or more) packets back to a Virtual Connect uplink port. This occurs when the packet that is sent back to the uplink port has a source MAC address that is the same as the one learned, and actively sending traffic on a Virtual Connect downlink port. This is an expected behavior for the Virtual Connect module. For any MAC address that is already learned in the Virtual Connect module MAC address table, and if this MAC address is also learned on a different port, the MAC learning process will experience a delay of approximately 2 seconds. If another packet with that same source MAC address is received on the original port where the MAC address was already learned, the MAC learning process on the different port is skipped altogether. If the packet that is sent back to the uplink port is a multicast or unicast flooded, the packet will reach the peer Virtual Connect module, and will be learned on a different port resulting in a "semi-permanent" incorrect MAC address entry. As a result, significant network traffic loss may occur. To determine if this issue has occurred, configure the netop account (see below), log into both Virtual Connect modules in the Logical Interconnect and execute the following command: show mac-address-table address < MAC address of the device experiencing traffic loss > Configure read-only CLI access Prerequisites: Infrastructure administrator or Network administrator privileges. The supported interconnect modules must be in configured state and in legacy security mode. The network operator (netop) account provides access to an advanced read-only CLI interface on the interconnect. The netop account password for an interconnect module can be configured from the HPE OneView GUI. Procedure: 1. From the main menu, select NETWORKING > Interconnects, and then select the interconnect to edit. 2. Select Actions > Configure read-only CLI access. 3. Change the netop password. If the interconnect is removed, replaced, or factory reset, then the password will be reset. A new password to access the netop account will have to be configured. 4. Click OK. When functioning properly, both Virtual Connect modules will indicate that the MAC address was learned on the same port. If there is a difference in which ports a MAC address was learned, the MAC Address table is out-of-sync.
Scope
In the scenario described above, the following interconnect modules: HPE Virtual Connect SE 100Gb F32 Module for Synergy running any firmware version. HPE Virtual Connect SE 40Gb F8 Module for Synergy running any firmware version.
Resolution
To avoid the issue described above, configure the external network switch to prevent traffic from reflecting back on a Virtual Connect module uplink port. If this issue has already occurred, generate a multicast or broadcast traffic such as an ARP request from the affected interface/MAC address. This will update the MAC address tables, and resolve the incorrect MAC address entries. Note: For additional information, refer to the user guide/documentation of the corresponding external network switch, and/or the user guide/documentation of the affected interface. RECEIVE PROACTIVE UPDATES : Receive support alerts (such as Customer Advisories), as well as updates on drivers, software, firmware, and customer replaceable components, proactively in your e-mail through HPE Support Alerts. Sign up for Support Alerts at the following URL: HPE Email Preference Center NAVIGATION TIP: For hints on navigating HPE.com to locate the latest drivers, patches and other support software downloads, refer to the Navigation Tips document. SEARCH TIP: For hints on locating similar documents on HPE.com, refer to the Search Tips document.
