Re: Priority Queue command behaviour

Hi Ravi,

I will take a stab at this.

Perhaps your PQ

R1(config)#priority-list 1 protocol http medium
> R1(config)#priority-list 1 default low

is simply not recognising your telnet attempt, albeit on port 80 as http
protocol? So it goes into the low queue.

Try changing http to another protocol and do telnets on its port number and
see.

Similarly change the line in the PQ that does work to use the new tcp port
number and compare the results.

Regards
Gary
----- Original Message -----
From: "Ravi Singh" <way2ccie_at_googlemail.com>
To: "Cisco certification" <ccielab_at_groupstudy.com>
Sent: Tuesday, June 16, 2009 12:12 PM
Subject: Priority Queue command behaviour

> Hi Group,
>
> I am digging out a pretty old thread on the priority-list usage
> command which is here ,( Courtesy - Jason Madsen )
>
> https://www.groupstudy.com/archives/ccielab/200810/msg01834.html
>
> The answer to this question was not definitive at that time and then
> it was lost in the GS archives.Also, I could not find any other place
> where this behaviour is explained , so here it goes
>
> I have found out that there is a difference between using
>
> priority-list 1 protocol http medium
>
> V/S
>
> priority-list 1 protocol ip medium tcp www
>
> Please look at the test below
>
> ..I have the following priority-list created
>
> R1(config)#priority-list 1 protocol ip medium tcp www
> R1(config)#priority-list 1 default low
> R1(config)#int f0/0
> R1(config-if)#priority-group 1
>
> R1#debug priority
> Priority output queueing debugging is on
>
> R1#telnet 10.1.12.2 80
> Trying 10.1.12.2, 80 ... Open
>
> *Jun 14 21:51:14.501: PQ: FastEthernet0/0: ip (tcp 80) -> medium
> *Jun 14 21:51:14.501: PQ: FastEthernet0/0 output (Pk size/Q 60/1)
> *Jun 14 21:51:14.505: PQ: FastEthernet0/0: ip (tcp 80) -> medium
> *Jun 14 21:51:14.505: PQ: FastEthernet0/0 output (Pk size/Q 60/1)
> *Jun 14 21:51:14.509: PQ: FastEthernet0/0: ip (tcp 80) -> medium
> *Jun 14 21:51:14.509: PQ: FastEthernet0/0 output (Pk size/Q 60/1)
>
> So this works as expected and the packets are sent to the medium
> queue. Now, if I change my priority-list to
> R1(config)#priority-list 1 protocol http medium
> R1(config)#priority-list 1 default low
>
> and initiate the traffic
>
> R1#debug priority
> Priority output queueing debugging is on
> R1#
> R1#telnet 10.1.12.2 80
> Trying 10.1.12.2, 80 ... Open
>
> *Jun 14 21:53:29.125: PQ: FastEthernet0/0: ip (defaulting) -> low
> *Jun 14 21:53:29.125: PQ: FastEthernet0/0 output (Pk size/Q 60/3)
> *Jun 14 21:53:29.129: PQ: FastEthernet0/0: ip (defaulting) -> low
> *Jun 14 21:53:29.129: PQ: FastEthernet0/0 output (Pk size/Q 60/3)
> *Jun 14 21:53:29.133: PQ: FastEthernet0/0: ip (defaulting) -> low
>
> The traffic goes into the low queue as a default. So there is a
> difference between the two commands. Has anyone encountered this
> behaviour before and does someone have a nice explanation to this .. I
> am using Version 12.4(7) BTW
>
> Thanks
> Ravi
>
>
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Received on Tue Jun 16 2009 - 22:16:28 ART