Rockwell ArmorStratix 5700 series, Инструкция по эксплуатации

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222 Rockwell Automation Publication 1783-UM007F-EN-P - September 2016
Chapter 7 Configure Switch Features
DHCP for Ring Devices
You can configure DHCP to assign IP addresses to devices connected to a ring
based on their positions in the ring. This feature makes sure that a replaced
device receives the expected IP address:
• A ring supervisor functions as the active ring DHCP server to assign IP
addresses to the participating nodes through two DLR ports.
• If enabled, a backup ring DHCP server runs on the backup ring
supervisor and obtains its reference table automatically from the active
ring DHCP server on the active ring supervisor. There can be multiple
backup ring DHCP servers in the ring.
• If the active ring DHCP server in the ring fails, the backup ring
supervisor becomes the active supervisor. The backup ring DHCP
server on the backup ring supervisor becomes the active ring DHCP
server and takes over IP assignment and renewal for the ring until one of
the following happens:
– The original active ring DHCP server is restored.
– A new active ring DHCP server is manually configured.
Figure 18 - DHCP Snooping Checkboxes
IMPORTANT DHCP for ring devices does not work with DHCP peristence, as described on
page 241 . Configure only one of these features on your switch.
IMPORTANT To enable a ring to assign correct addresses by using DHCP, you must check
both DHCP Snooping checkboxes on the DHCP page, as shown in Figure 18 .