A public-safety fabric team asks whether underlay PIM is still required if the pod uses EVPN-VXLAN with ingress replication for BUM. What is the sound conclusion?
Select an answer to reveal the explanation.
Short Explanation
If EVPN is building ingress-replication lists, the leaves already know whom to unicast BUM copies to—so you are not forced to keep a PIM megaphone in the underlay for that job. Turning PIM off does not magically delete bridging, and VXLAN absolutely can carry broadcast frames when the BUM path is designed.
Full Explanation
EVPN-VXLAN commonly uses ingress replication so BUM frames are unicast-encapsulated to remote VTEPs listed for a VNI, removing the requirement for underlay multicast/PIM for that BUM distribution method. Designs may still use underlay multicast for other reasons, but PIM is not inherently mandatory whenever EVPN is present. Disabling PIM does not redefine VNIs as L3-only, and VXLAN can encapsulate broadcast/multicast/unknown traffic when a BUM mechanism exists. Clarify BUM mode before assuming multicast dependencies.