Troubleshooting Cisco UCS Manager Overlapping VLANs: Resolving Critical Error

Resolving Critical Error: Overlapping VLANs in Cisco UCS Manager

Question

Cisco UCS Manager raises a critical error message that indicates that the system has overlapping Ethernet and FCoE VLANs.

All of the Ethernet traffic on the overlapping VLANs drops.

Which action resolves the issue?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

A.

The error message indicates that there are overlapping VLANs for both Ethernet and FCoE traffic in the Cisco UCS Manager. This can cause problems with connectivity and result in dropped Ethernet traffic. To resolve this issue, one of the following actions should be taken:

A. Modify the VLAN assignment to vNICs: This action involves changing the VLAN assignment for the vNICs (virtual network interface cards) in the system. The goal is to ensure that there are no overlapping VLANs for Ethernet and FCoE traffic. This can be done by reassigning VLANs to vNICs or creating new vNICs with different VLAN assignments.

B. Change the PIN groups on the vHBAs: This action involves changing the PIN (Priority-based Flow Control Initialization Protocol) groups on the vHBAs (virtual host bus adapters) in the system. This can help to prioritize FCoE traffic over Ethernet traffic and prevent dropped packets. However, this action alone may not resolve the issue of overlapping VLANs.

C. Modify the FCoE VLAN: This action involves modifying the FCoE VLAN configuration in the Cisco UCS Manager. The goal is to ensure that the FCoE VLAN is separate from the Ethernet VLANs and does not overlap with them. This can be done by creating a new FCoE VLAN or modifying the existing FCoE VLAN configuration.

D. Set the FCoE VLAN as the native VLAN on server uplinks: This action involves configuring the FCoE VLAN as the native VLAN on the server uplinks. The native VLAN is the default VLAN for untagged traffic on a switch port. By setting the FCoE VLAN as the native VLAN, FCoE traffic can be separated from Ethernet traffic and prevent overlapping VLANs.

Out of the four options, Option C or modifying the FCoE VLAN would be the most appropriate action to take. This is because the issue is related to overlapping VLANs between Ethernet and FCoE traffic. By modifying the FCoE VLAN configuration, it ensures that the FCoE VLAN is separate from Ethernet VLANs and does not overlap with them. This solution should help to resolve the issue of dropped Ethernet traffic.