Dell PowerConnect Brocade 300 Fabric OS Administrator's Guide v7.1.0 - Page 496

19 Supported topologies for ICL connections FIGURE 62 Full nine-mesh topology During an ICL break in the triangular topology, the chassis that has the connections of the other two is the main chassis. Any error messages relating to a break in the topology appear in the RASlog of the main chassis. For the Brocade DCX Backbone family only: If one ICL is broken but there is a regular ISL, the triangular topology holds given that the ISL cost is lower than the total cost through the ICL linear topology. If a direct ICL link between two chassis is broken, the triangular topology is considered broken when the ISL path between the two switches is a multiple hop. In this case, the triangular topology broken message is posted independently of the cost of the ISL path being lesser or greater than the ICL path between the two switches. Core-edge topology You can also connect the Brocade DCX 8510 Backbones in a core-edge topology. For example, Figure 63 shows six chassis connected in a core-edge topology (four edges and two cores). Although Figure 63 shows only the Brocade DCX 8510-8, each chassis can be either a Brocade DCX 8510-4 or a DCX 8510-8. You can have up to eight edges with DCX 8510-8 cores or up to four edges with DCX 8510-4 cores. Each line in Figure 63 represents four QSFP cables. The cabling scheme should follow the parallel example shown in Figure 59. 496 Fabric OS Administrator's Guide 53-1002745-02