RE: LLQ

Hi Scott,

First

You can't compare the forwarding rate on a switch vs a router.

Second,

Timeout 0 will dropped all packets on a router's ping:

R0#ping 150.1.15.1 size 1500 repeat 100000 time 0

Type escape sequence to abort.

Sending 100000, 1500-byte ICMP Echos to 150.1.15.1, timeout is 0 seconds:

......................................................................

......................................................................

......................................................................

...................................................................

Third,

I used real hardware on my test (masking my serial number just in case..)

R0#sh diag

Slot 0:

        C2651XM 2FE Mainboard Port adapter, 4 ports

        Port adapter is analyzed

        Port adapter insertion time 4w5d ago

        EEPROM contents at hardware discovery:

        Hardware Revision : 4.1

        PCB Serial Number : xxxxxxxxxxxx

        Version Identifier :

        Product (FRU) Number :

        Chassis Serial Number : xxxxxxxxxxx

        Part Number : 73-7756-06

        RMA History : 00

        RMA Number : 0-0-0-0

        Board Revision : B0

        Deviation Number : 0-0

        EEPROM format version 4

        EEPROM contents (hex):

          0x00: 04 FF 40 03 6F 41 04 01 C1 0B 46 4F 43 30 39 30

          0x10: 38 34 4B 4C 43 89 FF FF FF FF CB 12 FF FF FF FF

          0x20: FF FF FF FF FF FF FF FF FF FF FF FF FF FF C2 0B

          0x30: 46 54 58 30 39 32 30 41 31 39 42 82 49 1E 4C 06

          0x40: 04 00 81 00 00 00 00 42 42 30 80 00 00 00 00 FF

          0x50: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

          0x60: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

          0x70: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

        WIC Slot 0:

        Serial 1T WAN daughter card

        Hardware revision 1.0 Board revision J0

        Serial number xxxxxxxxx Part number 800-01514-01

        FRU Part Number WIC-1T=

        Test history 0x0 RMA number 00-00-00

        Connector type Wan Module

        EEPROM format version 1

        EEPROM contents (hex):

          0x20: 01 02 01 00 01 5E 68 18 50 05 EA 01 00 00 00 00

          0x30: 98 00 00 00 00 09 11 01 FF FF FF FF FF FF FF FF

        WIC Slot 1:

        Serial 1T WAN daughter card

        Hardware revision 1.0 Board revision J0

        Serial number xxxxxxxx Part number 800-01514-01

        FRU Part Number WIC-1T=

        Test history 0x0 RMA number 00-00-00

        Connector type Wan Module

        EEPROM format version 1

        EEPROM contents (hex):

          0x20: 01 02 01 00 01 5D FB 79 50 05 EA 01 00 00 00 00

          0x30: 98 00 00 00 00 09 10 01 FF FF FF FF FF FF FF FF

Edison Ortiz

Routing and Switching, CCIE # 17943

-----Original Message-----
From: Scott M Vermillion [mailto:scott_ccie_list_at_it-ag.com]
Sent: Tuesday, December 08, 2009 4:19 PM
To: Edison Ortiz
Cc: 'ron wilkerson'; 'Cisco certification'
Subject: Re: LLQ

Hey Ed,

Depending on the platform, you can generate several Mbps of traffic

with ICMP Echo. You simply need to specify the timeout as zero so

that there is no wait for a reply. It helps to specify a large echo

request size as well. The only time I ever saw a 6500 CPU spike to

and remain near 100% was when I used this technique to remotely

troubleshoot a throughput problem (the 6500 being the only "host" on

the network over which I had any control from afar).

Having said that, this is one area where Dynamips falls flat on its

face; I wouldn't trust any results involving Dynamips and any QoS

function, as there is no physical interface into which and out of

which to clock traffic. Dynamips is OK for practicing the

configuration of QoS, but not for capturing any meaningful results of

said configuration.

Regards,

Scott

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Received on Tue Dec 08 2009 - 16:40:30 ART