Traditional Layer 2 Issues in VXLAN Networks

VXLAN (Virtual Extensible LAN) encapsulates Layer 2 frames into UDP datagrams, transforming broadcast domains into Layer 3 traffic that the underlying physical network perceives only as IP traffic. Consequently, the underlay network is not aware of the VXLAN's Layer 2 MAC addresses, effectively mitigating traditional Layer 2 issues such as loops and broadcast storms. VXLAN does not rely on Spanning Tree Protocol (STP) for loop prevention, as the network utilizes Layer 3 routing.

However, VXLAN introduces other potential sources of loops or storms. Broadcast, Unknown unicast, and Multicast (BUM) traffic are (depending on the implementation) flooded across the VXLAN fabric to all VTEPs (VXLAN Tunnel Endpoints) participating in the same VXLAN segment (VNIs). Incorrect deployment may lead to problems, but mechanisms like split horizon filtering and Designated Forwarders (DFs) help prevent these issues.

Additionally, VXLAN can face control plane issues, multicast issues in the underlay, and inherent routing complexities. These are specific to VXLAN operations rather than conventional Layer 2 problems, underscoring the importance of proper VXLAN deployment to minimize network disturbances.

https://networklessons.com/vxlan/introduction-to-virtual-extensible-lan-vxlan

https://networklessons.com/vxlan/vxlan-flood-and-learn-multicast-data-plane