Administrator's Guide

3.12 OpenFlow topology screen
The OpenFlow screen displays a topology of discovered switches and end nodes in the controller
domain. The viewer creates and updates a graph of the network, and computes the broadcast tree
to avoid loops and broadcast storms. The shortest path is computed using Dijkstra’s graph search
algorithm. The viewer:
• Displays a topology of discovered switches and end nodes.
• Identifies the ports discovered on a given switch.
• Identifies the shortest path between two nodes.
• Provides node identification options (MAC or IP address label).
• Provides a view of switch port identifiers, active flow rules, and a tool for testing flow rule
options.
CAUTION: Do not allow a loop between the OpenFlow and non-OpenFlow portions of your
network unless you enable Spanning Tree Protocol on the non OpenFlow devices operating in the
network
NOTE: In a topology where two or more controlled switches connect to the same uncontrolled
switch, the controller will not learn the location of hosts connected to the uncontrolled switch.
3.12.1 Displaying the network toplogy
The OpenFlow Topology screen includes the switches and end-nodes in the controller domain.
Figure 10 Topology viewer
3.12 OpenFlow topology screen 39