Refer to the exhibit.

Which option describes the reason for this message in a GLBP configuration?

A.
Unavailable GLBP active forwarder

B.
Incorrect GLBP IP address

C.
HSRP configured on same interface as GLBP

D.
Layer 2 loop

Explanation:
This section provides information you can use to troubleshoot your configuration.
%GLBP-4-DUPADDR: Duplicate address
The error message indicates a possible layer2 loop and STP configuration issues. In order to resolve this issue, issue the show interface command to verify the
MAC address of the interface. If the MAC address of the interface is the same as the one reported in the error message, then it indicates that this router is receiving
its own hello packets sent. Verify the spanning-tree topology and check if there is any layer2 loop. If the interface MAC address is different from the one reported in
the error message, then some other device with a MAC address reports this error message.
Note: GLBP members communicate between each other through hello messages sent every 3 seconds to the multicast address 224.0.0.102 and User Datagram
Protocol (UDP) port 3222 (source and destination). When configuring the multicast boundary command, permit the Multicast address by permit 224.0.0.0
15.255.255.255.

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