22 Rockwell Automation Publication 750COM-UM009A-EN-P - May 2017
Chapter 1 Getting Started
Choose an Ethernet Switch
If the built-in EtherNet/IP interface is used to communicate with a
controller that has multicast connections, a managed switch that
supports IGMP snooping is suggested. EtherNet/IP implicit (I/O)
messaging can be configured to use IP multicast to distribute I/O
control data, which is consistent with the CIP-based network Producer/
Consumer model. If multiple built-in EtherNet/IP interfaces are
connected to the switch in a redundant configuration, a managed switch
is required. A managed switch also provides useful diagnostic features
such as port mirroring.
The built-in EtherNet/IP interface, RSLogix 5000 software version 20,
Studio 5000 Logix Designer application version 21 and later, and a
Logix controller all support unicast connections. Unicast is the default
setting when adding the drive to the I/O controller. When all built-in
EtherNet/IP interfaces are installed as unicast devices, then an IGMP
snooping (managed) switch is not needed.
The choice of a switch involves many factors. See publication ENET-
RM002 for details.