Understanding Multihomed CE-to-PE VXLAN Environment:
In a VXLAN environment using EVPN signaling, multiple PEs (Provider Edge devices) can be
connected to the same CE (Customer Edge device). This setup is referred to as multihoming, where a
CE device has multiple connections to the network to ensure redundancy and load balancing.
Role of the Designated Forwarder:
The designated forwarder (DF) is a mechanism used in EVPN to manage the forwarding of broadcast,
unknown unicast, and multicast (BUM) traffic in a multihomed environment. The DF is selected to
ensure that only one of the PEs forwards this type of traffic to the CE, preventing loops and
unnecessary duplicate packets.
Avoiding Duplicate Packets:
Without a designated forwarder, all PEs connected to a multihomed CE could potentially forward the
same packet to the CE, resulting in duplicate packets. This duplication can cause issues with packet
processing on the CE, leading to inefficiencies and potential network problems.
Conclusion:
Option D: Correct—The designated forwarder is essential to prevent duplicate packets from being
received on multihomed hosts, ensuring that only one PE forwards BUM traffic to the CE.