"Ethernet1/1 is down (DCX rcvd Multiple MSAPs)"

[thomas_daley]

I have 2 Nexus 5020 that were working fine with a Brocade MLX-8 Router (customer's core).  The customer decided to move a few interfaces around on the Brocade and when the did the ports error disabled on the Nexus.  A shut/no shut resolved the issue but I have never seen this error before.  Can someone tell me what that error message means?

Thanks,

Thom

[mipetrin]

Hi Thom,

DCBX negotiation uses LLDP (frames with Ether Type 0x88cc). An LLDP neighbor is identified by its logical MAC Service Access Identifier (MSAP). The logical MSAP is a concatenation of the chassis ID and port ID values transmitted in the LLDPDU.

The error message that you were seeing will occur if the adapter uses two different MAC addresses in LLDP PortId TLV without a link flap. This could happen if the adapter changes the MAC address without flapping the port. A change of the MSAP without toggling the link is not accepted.

A shut / no shut will clear the issue.

Further information regarding Nexus 5000 FCoE and LLDP is avilable via the following document

Configuring FCoE
http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/configuration/guide/cli/fcoe.html

Thanks,
Michael

[thomas_daley]

Thanks Michael, I appreciate the information.

Thom

[robert.horrigan]

Thanks!  great info