Output from "show controller switch"

[jrgarrigues]

Greetings,

My organization is pushing new operating systems out over many LANs using

Symantec Ghost. Getting a lot of help calls when the administrators try to

push during production hours, and, most of the time, when they are pushing

this traffic over older 29xx series switches (2900, 2924, 2948, and 2950).

Indications point to the fact that they are just pushing the devices too

hard; I usually check "show proc cpu" to find the CPU is running very high

and "show log" generally displays a lot of collisions, but few, if any,

errors.

I'm using the "show controller switch" command to determine whether or not

the switch is operating at maximum bandwidth capability. The only problem is

that I cannot find a reference for the metrics this is displaying.

"If the Total Allocation reaches or is over the Congestion Threshold amount,

the switch is experiencing considerable network activity near its full

capacity." (see example below) This is all well and fine, and I am

convinced, but I want to have a definition of what these hexidecimal numbers

indicate (i.e. is this some kind of measurement that I can convert when I am

explaining the situation?).

Thanks in advance,

John

Switch#show controller switch

Switch registers:

Device Type : 0x00040273

Congestion Threshold : 0x00000E95 ******

Peak Total Allocation : 0x0000001A

Total Allocation : 0x00000000 ******

Peak Total Bandwidth : 0x00000020

Total Bandwidth : 0x00000000

Total Bandwidth Limit : 0x000003DE

Lower Bandwidth Limit : 0x000003DE

Switch Mode : 0x00040000

Switch#

[smahbub]

check the below link for reference

http://www.cisco.com/en/US/products/hw/switches/ps607/products_tech_note09186a0080094e78.shtml

[jrgarrigues]

Thanks for the response, this is actually where I started. This is just about the most informative resource I've been able to locate on the command "sh controller switch"; but what I am looking for is some sort of measure or metric from which the response to the command is derived. i.e. what calculations does my switch make to give me this answer? Is it the combination of the maximum bandwidth of all available ports? etc...

---------------------------------------------------

...from the link:

"The Total Bandwidth Limit varies between different 2900XL and 3500XL models. When the Total Bandwidth reaches the Total Bandwidth Limit value, the switch has reached its full bandwidth capacity and begins to drop packets. The Peak Total Bandwidth is the highest value attained by the Total Bandwidth since the last time the show controller switch command was executed. Note, the values for the above parameters are in hexadecimal.

The Congestion Threshold value is used as conservative value for the maximum global buffer utilization. When the buffer utilization noted by Total Allocation reaches this value, the switch may drop frames. The Peak Total Allocation value shows the highest value attained by the Total Allocation since the last time the show controller switch command was executed. It is possible for the Peak Total Allocation and/or the Total Allocation to be greater than Congestion Threshold. If the Total Allocation reaches or is over the Congestion Threshold amount, the switch is experiencing considerable network activity near its full capacity."

--------------------------------------------------

Thanks,

John

[mr7]

Hi all,

If my switch is C2950, how can I knwo the back plane usage? I found the "show controller switch" cannot be used at these platform.

Thx,

BBD

[r.cheung]

You can graph the backplane usage with MRTG.

Otherwise, is your network multicast enabled, so that multiple ghost sessions wont have a multiplicative effect on the bandwidth consumption? Switches should be enabled for cgmp by default; you'll just have to enable cgmp on the router interface to the switches, so users off switch ports not involved in the ghosting will not receive the multicast traffic. Remember that a switch floods multicast packets out all ports unless enabled for CGMP, etc.

HTH,

Rick