Network - BUM Traffic

In networking, BUM traffic stands for Broadcast, Unknown Unicast, and obsidian/notes/Multicast traffic. It refers to three types of traffic that need special handling in Ethernet-based networks, especially in environments like VXLAN or traditional Layer 2 networks. Here's a breakdown:

1. Broadcast traffic: Packets sent to all devices in a broadcast domain. For example, ARP (Address Resolution Protocol) requests.
2. Unknown Unicast traffic: When the destination MAC address is not in the switch's MAC address table, the packet is flooded to all ports except the source port.
3. Multicast traffic: Packets sent to a group of devices that have subscribed to a particular multicast group.

BUM traffic is typically flooded to all devices in a Layer 2 domain, and it can lead to inefficiencies if not managed well, especially in large networks like those using VXLAN, where mechanisms are needed to control and limit this type of traffic. VXLAN uses features like IGMP snooping and multicast groups to help contain BUM traffic.

Links:

https://networklessons.com/vxlan/vxlan-mp-bgp-evpn-l2-vni