Discovering broadcast and error storms
One of the most troublesome problems in communication networks is the broadcast and error storms. These problems can happen because of layer 2 loops, layer-2-based attacks, a problematic network adapter, or a service that sends packets to the network.
In this chapter we will provide some basic recipes on how to find, isolate, and solve these types of problems.
Tip
A broadcast storm is when you get thousands and even tens of thousands of broadcasts per second. In most cases it would lock out the network completely.
Getting ready
In these types of problems, you will usually be called on to solve the network is very slow or network has stopped working problems.
Several important facts to remember are:
Broadcasts are not forwarded by routers.
Broadcasts are not forwarded between VLANs (this is why VLANs are called broadcast domains), so every VLAN is a single broadcast domain.
Error packets are not forwarded by LAN switches (at least not through the good ones).
Multicasts...
