simple question...maybe

To a large extent bandwidth sharing is the natural behaviour of networks. It's just what they do. TCP in particular does a reasonable job in many circumstances although it seems that established sessions get preference over new sessions.

Consider the reverse problem, given your described topology how could you arrange to get un 'unfair' share of the bandwidth? This would be quite hard to arrange.

"all ports share the 10Mbs internet connection equally" I doubt that there is any such facility built into any switches however you could I suppose use an external computer to figure out how many ports are up and then to apply rate limiting to those ports.

Well I know about using CAR with IOS on routers, but what about switches? More specifically the lower end units like the 2900 and 3600 series?

System image file is "flash:c3560-i5-mz.121-19.EA1c/c3560-i5-mz.121-19.EA1c.bin" cisco WS-C3560-24PS

Can do traffic shaping to a rate but is is pretty weird to configure.

This lot limits certain traffic to about 150k or something. I had to calibrate it by trial and error. The port is running at

10M to increase the granularity of the control in the area that I wanted.

You also have to map QoS values to queues. It was all a bit of a nightmare but did seem to work

mls qos map cos-dscp 0 8 16 26 32 46 48 56 mls qos srr-queue input bandwidth 50 50 mls qos srr-queue input cos-map queue 1 threshold 2 1 mls qos srr-queue input cos-map queue 1 threshold 3 0 mls qos srr-queue input cos-map queue 2 threshold 1 2 mls qos srr-queue input cos-map queue 2 threshold 2 4 6 7 mls qos srr-queue input cos-map queue 2 threshold 3 3 5 mls qos srr-queue input dscp-map queue 1 threshold 2 9 10 11 12 13 14

15 mls qos srr-queue input dscp-map queue 1 threshold 3 0 1 2 3 4 5 6 7 mls qos srr-queue input dscp-map queue 1 threshold 3 32 mls qos srr-queue input dscp-map queue 2 threshold 1 16 17 18 19 20 21 22 23 mls qos srr-queue input dscp-map queue 2 threshold 2 26 33 34 35 36 37 38 39 mls qos srr-queue input dscp-map queue 2 threshold 2 48 49 50 51 52 53 54 55 mls qos srr-queue input dscp-map queue 2 threshold 2 56 57 58 59 60 61 62 63 mls qos srr-queue input dscp-map queue 2 threshold 3 24 25 27 28 29 30 31 40 mls qos srr-queue input dscp-map queue 2 threshold 3 41 42 43 44 45 46 47 mls qos srr-queue output cos-map queue 1 threshold 3 3 5 mls qos srr-queue output cos-map queue 2 threshold 3 0 1 2 4 6 7 mls qos srr-queue output dscp-map queue 1 threshold 3 24 26 46 mls qos srr-queue output dscp-map queue 2 threshold 2 9 10 11 12 13 14 15 mls qos srr-queue output dscp-map queue 2 threshold 3 0 1 2 3 4 5 6 7 mls qos srr-queue output dscp-map queue 2 threshold 3 16 17 18 19 20 21 22 23 mls qos srr-queue output dscp-map queue 2 threshold 3 25 27 28 29 30 31 32 33 mls qos srr-queue output dscp-map queue 2 threshold 3 34 35 36 37 38 39 40 41 mls qos srr-queue output dscp-map queue 2 threshold 3 42 43 44 45 47 48 49 50 mls qos srr-queue output dscp-map queue 2 threshold 3 51 52 53 54 55 56 57 58 mls qos srr-queue output dscp-map queue 2 threshold 3 59 60 61 62 63 mls qos queue-set output 1 buffers 20 20 20 40 mls qos queue-set output 2 buffers 40 40 10 10

interface FastEthernetx/y description To The Internet no ip address srr-queue bandwidth shape 25 60 0 0 srr-queue bandwidth limit 10 queue-set 2 priority-queue out no mdix auto

Thanks I did some more digging, now that I was using the right term, and found that the switches all the way down to the 2950 will do rate limiting with the Enhanced Image and the 3750 with the "IP Services Image" can do rate limiting associated with time-based ACLs.

In the end it was for nothing since I was working with someone that just couldn't understand why the switches he saw in the local computer store were $150.00 and the one that would do what he wanted was thousands more.