In a collapsed core design, which two benefits are provided by a second-generation Cisco MDS director? (Choose two

Single-Switch Collapsed-Core Design

The collapsed-core single-switch design takes a traditional core-edge topology and collapses it into a single chassis. Instead of using many small switches to provide sufficient port density, a single chassis with a high port count replaces the smaller switches. This design reduces the number of ISLs required in the network so that all available ports can be deployed for host or storage connections, leading to 100 percent port design efficiency.

In Figure below, the backplane of the MDS in the collapsed-core design replaces all the ISL links. This design can also provide a lower fan-out ratio than the multiple small switches because the availability of more advanced blades for the MDS. Empty slots on the MDS can support future growth on new line cards.

The collapsed-core design on a first-generation switch has limited capabilities with regard to high availability. With later-generation Cisco MDS series switches, dual redundant crossbar switch fabrics are used on all director switches to provide low-latency, highthroughput, nonblocking, and non-oversubscribed switching capacity between line card modules. In addition, the port bandwidth reservation feature guarantees dedicated performance for those devices that require it.

Note Second-generation MDS 9500 series director switches are fully redundant with no single point of failure with dual supervisors, crossbar switch fabrics, clock modules, or power supplies. Nonetheless, note that this design still has a single point of failure with the one chassis.

Reference: Designing Cisco Network Service Architectures (ARCH) Foundation Learning Guide – 3rd Edition, Pages 333 – 334

if it is “low fan-out ratio” then it will be a correct answer.