Cataylst 3750 Bandwidth limiting

[oguarisco]

Hi,

on cat3750 you can limit the Bandwidth on a n egress interface using the SRRcommand:

srr-queue bandwidth limit "weight1"

the weight1 is a variable in the range from 10 to 100 (default)

This means that in a 3750G a giga interface the egress queue can be limited only to 100Mbit/s (setting the weight1=10)...or the siwtch is able to interpret the weight in correlation of the port settings

for example a gigabit port is connected to a device and the settings are 100FD

if the srr weight1 is set equal to 10 then the egress BW is 100Mbits, seeing it's a giga interface, or 10Mbit/s seeing it's a giga interface BUT connected as 100FD ?

thanks for replay

Omar

[pkhatri]

Hi Omar,

While I am not in a position to log into a 3750 and verify this right now, I am pretty sure that the setting will apply to the speed at which the interface is connected. This is because QoS parameters act on the bandwidth as dislayed by the 'show interface' command. When a Gig interface is connected at 100Mbps,the bandwidth is set to 100000k, and therefore that is what the 'srr-queue bandwidth limit' command should act on.

Hope that helps - pls do rate the post if it does.

Paresh

[m.benhassine]

Under which IOS image could you find this command?

For example, using a stack of three 3750G, running under the 12.2 (25)-SEC2, the command is as follows:

Switch(config)#mls qos srr-queue input bandwidth ?

<1-100> enter bandwidth weight for queue id 1

and there are 2 queues

or

Switch(config)#mls qos srr-queue output ?

cos-map Configure cos-map for a queue id

dscp-map Configure dscp-map for a queue id

1-100 are weights that act on a port settings. Seeing that traffic is serviced depending upon

its class of service (CoS) or differentiated services code point (DSCP) designation and this command is from commands conditioning delivery.

[oguarisco]

Hi Mohamed,

starting from version 12.2(25)SEC and following...

Please take note that the command is available only on interface configuration and not in global configuration

switch (config-if)#srr-queue bandwidth limit ?

<10-90> enter bandwidth limit for interface as percentage

hth

Omar