D-Link DES-3326 User Manual - Broadcast Storms
24-port NWay Ethernet Switch User’s Guide
Switch Management and Operating Concepts
71
network administrator has to take any action in the configuration
process.
Before loading TCP/IP with an address acquired from the DHCP
server, DHCP clients check for an IP address conflict by sending
an Address Resolution Protocol (ARP) request containing the
address. If a conflict is found, TCP/IP does not start, and the
user receives an error message. The conflicting address should
be removed for the list of active leases or it should be excluded
until the conflict is identified and resolved.
Broadcast Storms
Broadcast storms consist of broadcast packets that flood and/or
are looped on a network causing noticeable performance
degradation and in extreme cases, network failure. Broadcast
storms can be caused by malfunctioning NICs, bad cable
connections and applications or protocols that generate
broadcast traffic, among others.
Broadcast storms have long been a concern for network
administrators with routers traditionally being used to prevent
their occurrence, and if that failed, limit their scope. However,
with the advent of VLANs, switches are now able to limit
broadcast domains better and cheaper than routers. Also, many
switches, including the DES-3226, have broadcast sensors and
filters built into each port to further control broadcast storms.
Segmenting Broadcast Domains
VLANs can be used to segment broadcast domains. They do this
by forwarding packets only to ports that are members of the
same VLAN. Other parts of the network are effectively shielded.