Im at the policing and shaping section of the exam certification guide, and its very hardcore stuff in my opinion. Just finished the section on 3550 and 3560 ingress/egress queuing and scheduling methods. Wow, thats really something i gotta get my head around.
One thing to note, is the fact that the switches use an internal DSCP value to map to all CoS values. Another is how the queues work in each switch model. The 3550 switch has 1 ingress queue and 4 egress queue with queue 4 able to be used as a priority queue. The 3560 switch has two ingress queue’s and can therefor apply some sort of scheduling on what to process. It also has 4 egress queues, where default you can configure a priority queue on queue 1 (configurable). Either SRR or SRR (yes, you read correctly), Shared-Round-Robin or Shaped-Round-Robin can be used, shaping providing a means to not starve non-priority queues.
I also ordered 3 new books which needs thorough reading:
- QoS exam certification guide by Wendell Odom.
- Developing IP multicast networks by Beau Williams
- Internet Routing Architectures
On top of that I ordered a 3550 switch to add to my rack. That puts me at 2 3560’s and a 3550, so in order to support the full IP expert topology i still need another 3550.
Okay, im heading home now. See you!