From: Jared Scrivener (jscrivener@ipexpert.com)
Date: Thu Jan 29 2009 - 03:01:00 ARST
Hey Mark,
The first example assumes a two-colour policer, the second example assumes a
three-colour policer.
Effectively, the CIR is the average rate you've paid to send data at and the
PIR is the maximum rate you can send data at.
Often, the PIR is equal to the access rate on the link (AR). When this
occurs you can use a two-colour policer - traffic up to the CIR is
conforming and traffic between the CIR and PIR (or AR as they are equal) is
excess.
If the PIR (which is the fastest you are ever "allowed" to send data) is
less than the AR on the link then there are 3 categories. The CIR is the
average speed you can send at (conforming), the PIR is the speed you are
allowed to burst up to (exceeding) and the AR is the physical speed you
*can* go up to but are NOT allowed to (violating).
In your question you've defined the CIR and the PIR the same in both
examples. However, when using the second syntax the router assumes that
there is going to be a difference between the PIR and the AR on the link and
will create that "violating" action so that you can punish that traffic
accordingly.
Cheers,
Jared Scrivener CCIE3 #16983 (R&S, Security, SP), CISSP
Technical Instructor - IPexpert, Inc.
Telephone: +1.810.326.1444
Fax: +1.810.454.0130
Mailto: jscrivener@ipexpert.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Mark
Stephanus Chandra
Sent: Wednesday, 28 January 2009 11:50 PM
To: ccielab@groupstudy.com
Subject: Police CIR vs PIR
Hi Guys
I just want a confirmation regarding Traffic Policing :
If I said
Police 128000 4000 8000 conform-action transmit exceed-action transmit,
is it the same with :
police cir 128000 pir 256000 ?
Can u tell me what is the difference between these two statement:
When I use CIR I get this configuration :
R2(config)#do sh policy-map interface fast 0/0
FastEthernet0/0
Service-policy output: mark
Class-map: QOS (match-all)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: access-group 101
police:
cir 128000 bps, bc 4000 bytes
conformed 0 packets, 0 bytes; actions:
transmit
exceeded 0 packets, 0 bytes; actions:
transmit
conformed 0 bps, exceed 0 bps
cause when I use PIR I get this configuration :
R2(config-if)#do sh policy-map interface fast 0/0
FastEthernet0/0
Service-policy output: mark
Class-map: QOS (match-all)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: access-group 101
police:
cir 128000 bps, bc 4000 bytes
pir 256000 bps, be 8000 bytes
conformed 0 packets, 0 bytes; actions:
transmit
exceeded 0 packets, 0 bytes; actions:
drop
violated 0 packets, 0 bytes; actions:
drop
conformed 0 bps, exceed 0 bps, violate 0 bps
Thanks in advance
Regards
Mark
Blogs and organic groups at http://www.ccie.net
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