06-07-2007 12:27 PM - edited 03-05-2019 04:34 PM
We have a 3750 stack include 48T and G-24T switch. The server is 1000/Full and workstation is 100/full. And we enable mls qos.
I got a very slow speed when copying file from server to workstation even off hour. From the sniffer it showed that some packet were lost. But I did show interface and did not see any drop packets. Where are those packet?
06-08-2007 02:28 AM
Please more infos: server/workstation OS, switch configuration, ...
Regards
Andrea
06-08-2007 04:57 AM
Here is the configuration:
===========================================
mls qos srr-queue input bandwidth 25 75
mls qos srr-queue input threshold 1 40 40
mls qos srr-queue input buffers 50 50
mls qos srr-queue input priority-queue 2 bandwidth 25
mls qos
!
interface GigabitEthernet2/0/1
description Server
switchport access vlan 10
srr-queue bandwidth share 10 20 40 80
srr-queue bandwidth shape 0 0 0 0
spanning-tree portfast
interface GigabitEthernet1/0/1
description Workstation
switchport access vlan 1
srr-queue bandwidth share 10 20 40 80
srr-queue bandwidth shape 0 0 0 0
spanning-tree portfast
===========================================
And the server is win2003, and workstation is win2000. This is a 3750 stack. I don't mark any traffic and all traffic is Cos 0.
06-08-2007 05:09 AM
have you already investigate it with a sniffer (like ethereal)?
Some years ago I've found a MS bug on Win2k server (with WinXP SP1 clients) about SMB retransmissions ... I don't know if that could help you, but ...
Set also duplex/speed statically on switch/server interface ... just a best practice for prevent a duplex mismatch or slow negotiation ...
HTH
Andrea
06-12-2007 12:38 PM
I did a sniff on the traffic. And it showed that some packets were dropped in the FE port. Dose anyone has a good mls qos configuration for this situation? I tried different mls qos setting, but everytime I enable mls qos the speed slow down dramatically.
11-02-2007 09:29 AM
What version of code are you running on the 3750s?
11-02-2007 12:23 PM
Following the previous post there are fundamental differences between 12.1 and 12.2 concerning QoS.
Certainly from 12.2 there is an additional queue-set for Gigabit interfaces. Previously all interfaces by default have queue-set 1 applied and therefore are restricted by thresholds configured regardless of port type.
Typically by default COS 0 or untrusted traffic will be mapped to the egress queue-4 unless you have changed your COS mappings.
Is there a specific reason why you have configured SRR in the first instance? You do not have any trust on either of the ports and will therefore be untrusted. Consequently all queue will be services accordingly, and COS 0 traffic will be the first to be dropped.
Congestion commonly occurs on egress, and your configuration unfortunately does indicate any output cos maps, output thresholds or buffers.
See the following example, like I said queue-set 1 is applied to FE and queue-set 2 is applied to GE.
mls qos map cos-dscp 0 8 16 26 32 46 48 56
mls qos srr-queue input bandwidth 90 10
mls qos srr-queue input threshold 1 8 16
mls qos srr-queue input threshold 2 34 66
mls qos srr-queue input buffers 67 33
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 33 34 35 36 37 38 39 48
mls qos srr-queue input dscp-map queue 2 threshold 2 49 50 51 52 53 54 55 56
mls qos srr-queue input dscp-map queue 2 threshold 2 57 58 59 60 61 62 63
mls qos srr-queue input dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue input dscp-map queue 2 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output cos-map queue 1 threshold 3 5
mls qos srr-queue output cos-map queue 2 threshold 3 3 6 7
mls qos srr-queue output cos-map queue 3 threshold 3 2 4
mls qos srr-queue output cos-map queue 4 threshold 2 1
mls qos srr-queue output cos-map queue 4 threshold 3 0
mls qos srr-queue output dscp-map queue 1 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue output dscp-map queue 2 threshold 3 48 49 50 51 52 53 54 55
mls qos srr-queue output dscp-map queue 2 threshold 3 56 57 58 59 60 61 62 63
mls qos srr-queue output dscp-map queue 3 threshold 3 16 17 18 19 20 21 22 23
mls qos srr-queue output dscp-map queue 3 threshold 3 32 33 34 35 36 37 38 39
mls qos srr-queue output dscp-map queue 4 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue output dscp-map queue 4 threshold 3 0 1 2 3 4 5 6 7
mls qos queue-set output 1 threshold 1 138 138 92 138
mls qos queue-set output 1 threshold 2 138 138 92 400
mls qos queue-set output 1 threshold 3 36 77 100 318
mls qos queue-set output 1 threshold 4 20 50 67 400
mls qos queue-set output 2 threshold 1 149 149 100 149
mls qos queue-set output 2 threshold 2 118 118 100 235
mls qos queue-set output 2 threshold 3 41 68 100 272
mls qos queue-set output 2 threshold 4 42 72 100 242
mls qos queue-set output 1 buffers 10 10 26 54
mls qos queue-set output 2 buffers 16 6 17 61
Depending on your traffic profile, you may need to service queue depending on whether you have voice and/or videowhether. If you have neither of these requirements then configure SRR on the interfaces as follows:-
srr-queue bandwidth share 5 5 10 80
srr-queue bandwidth shape 0 0 0 0
Regards
Allan.
11-02-2007 01:20 PM
There is also this bug which you might be running into: CSCsc96037
Configuring Quality of Service on a CAT3560 or CAT3750 running any IOS can cause certain TCP
applications such as NFS to run slower.
This issue will be resolved in Cisco IOS 12.2(25)SEE1.
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