ion 266 Bandwidth 40 (%) Max Threshold 64 (packets) (pkts matched/bytes matched) 78903/4669112 (depth/total drops/no-buffer drops) 0/0/0 Class-map: class-default (match-any) 23750755 packets, 2030244008 bytes 5 minute offered rate 887000 bps, drop rate 4000 bps Match: any Queueing Flow Based Fair Queueing Maximum Number of Hashed Queues 256 (total queued/total drops/no-buffer drops) 12/16501/0 Notice that the default queue is dropping packets at a rate of 4,000 bps. As soon as I change the HTTP queue to be allowed only 5 percent instead of 40 percent, the router almost completely stops dropping packets in the class-default queue: Class-map: HTTP (match-any) 86935 packets, 5150618 bytes 5 minute offered rate 1000 bps, drop rate 0 bps Match: access-group 101 86935 packets, 5150618 bytes 5 minute rate 1000 bps Queueing Output Queue: Conversation 266 Bandwidth 5 (%) Max Threshold 64 (packets) (pkts matched/bytes matched) 86204/5106232 (depth/total drops/no-buffer drops) 0/0/0 Class-map: class-default (match-any) 26519010 packets, 2404610690 bytes 5 minute offered rate 849000 bps, drop rate 0 bps Match: any Queueing Flow Based Fair Queueing Maximum Number of Hashed Queues 256 (total queued/total drops/no-buffer drops) 0/32252/0 The trick here is that the configuration of one queue directly affected the behavior of another queue-specifically, the one beneath it. In this case, there was nothing I could have done to the class-default queue to increase its performance; the changes had to be made to the queue above it. Troubleshooting a Converged Network Default Queue Too Small The size of the class-default queue is not directly configurable. If the queue is too small, either the link is too small or the other queues are too large. In either case, you'll end up dropping packets in the class-default queue. Default Queue Too Large I would argue that the default queue cannot be too large. If you have a large class-default queue, you have ample capacity and life should be good-for now, anyway! Chapter 34: The Converged Network