cisco 3750 switch port issue-

[amitesh.pandey1]

Hi All i have a switch of 48 port 3750.

All the ports are having same configuratio nhwoever, when a user goes to port 25 and beyond he is facing internet slwoness issues and not with anyone the first 24 ports.

all the ports are having same qos settings and DHCP is configured for client.

Let me know what should i check for this.

Thanks in advance.

Amitesh p

[Jerry Paul]

This is not fault of your switch.

Divide users in VLANs.

Configure QoS and set separate bandwidth for wvwery VLAN.

Jerry Paul

www.thenetworkhardware.com

[amitesh.pandey1]

Jerry,

I have checked on the VLAN front. there are spare Ips in allocated VLAN and the system is taking IP from DHCP on the ports that are affected with slowness. I need to understand that QoS are not port based So what can be the reason that QoS is afecting my situtaiton. Also, the qos settings on the ports are identical. 

Let me know what else should i check to narrow down the issue.

[Jerry Paul]

Remove QoS and check the results.

Let me know about the effects.

Jerry Paul

www.thenetworkhardware.com

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

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Posting

You can first try show interface, and see if there are any drops there.

Then there are other commands that will give you drops per ASIC or per hardware queue.  Unfortunately, I'm not able to access a 3750 at the moment to jog my memory what those commands are.

Be warned, though, I recall different versions of 3750 IOS, I recall, have bugs displaying some of their interface/ASIC/queue stats.

[rosaho]

This discussion has been reposted to the LAN, Switching and Routing community.

[Aref Alsouqi]

Hi,

Please post your sanitized configuration for review.

Regards | Aref.

[chinmoy.boruah1]

Dear Amitesh,

Assuming that you are connecting only end devices on the switch, is portfast been enabled on the ports?

With regards

Chinmoy

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

The 3750 provides 2 MB of buffer RAM to each bank of 24 copper ports (and to the uplink ports).  So, it's possible, if ports 25..48 are much more active than ports 1..24, individual ports in the range 25..48 may perform slower.

What to look for is drops per port, especially if there seem to be more, proportional for one bank of 24 ports than the other.

[amitesh.pandey1]

Can you please tell me how i will check for drops per ports. I am not seeing CRC FEC errors. on those ports.

Thanks for your help.

Amitesh P.