Re: mls qos map policed-dscp

Actually I don't need a capture. I can track COS markings with a policy map.
I configured SW2-R2 as a trunk. Here is R2's config now:

class-map match-all COS5
 match cos 5
!
policy-map TRACK-COS
 class COS5
!
interface Ethernet0/0.12
 encapsulation dot1Q 12
 ip address 192.168.0.2 255.255.255.0
 no snmp trap link-status
 service-policy input TRACK-COS

R1#ping 192.168.0.2 re 100

Type escape sequence to abort.
Sending 100, 100-byte ICMP Echos to 192.168.0.2, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (100/100), round-trip min/avg/max = 1/3/4 ms
R1#

R2#sho policy-map interface
 Ethernet0/0.12

  Service-policy input: TRACK-COS

    Class-map: COS5 (match-all)
      110 packets, 12980 bytes
      30 second offered rate 0 bps
      Match: cos 5

    Class-map: class-default (match-any)
      0 packets, 0 bytes
      30 second offered rate 0 bps, drop rate 0 bps
      Match: any

I am still using the default mappings.

Bryan Bartik
CCIE #23707, CCNP
Sr. Support Engineer - IPexpert, Inc.
URL: http://www.IPexpert.com

On Sat, May 2, 2009 at 9:46 PM, Bryan Bartik <bbartik_at_ipexpert.com> wrote:

> Here is my results. Please let me know if I am missing something, this was
> a rather hastily put together test, but as you can see I did not configure
> mappings. Only the default exists.
>
> [R1] e0/0 ------ f0/1 [SW1] ------ [SW2] f0/2 ------ e0/0 [R2]
>
> R1 and R2 are on vlan 12, subnet 192.168.0.0/24. Switches are 3560s and at
> DEFAULT. Here is what I configure, from the start:
>
> On SW1:
>
> Switch>en
> Switch#conf t
> Enter configuration commands, one per line. End with CNTL/Z.
> Switch(config)#host SW1
> SW1(config)#int f0/13
> SW1(config-if)#sw tr e dot
> SW1(config-if)#sw mo tr
> SW1(config-if)#int f0/1
> SW1(config-if)#sw mo a
> SW1(config-if)#sw ac v 12
> % Access VLAN does not exist. Creating vlan 12
> SW1(config-if)#mls qos
> SW1(config)#int f0/1
> SW1(config-if)#mls qos trust dscp
>
> On SW2:
>
> Switch>en
> Switch#conf t
> Enter configuration commands, one per line. End with CNTL/Z.
> Switch(config)#host SW2
> SW2(config)#int f0/2
> SW2(config-if)#sw mo a
> SW2(config-if)#sw ac vlan 12
> % Access VLAN does not exist. Creating vlan 12
> SW2(config-if)#int rang f0/14 - 24
> SW2(config-if-range)#shut
> SW2(config-if-range)#int f0/13
> % Command exited out of interface range and its sub-modes.
> Not executing the command for second and later interfaces
> SW2(config-if)#sw t e d
> SW2(config-if)#sw mo tr
> SW2(config-if)#monito sess 1 sou int f0/13
> SW2(config)#monito sess 1 des int f0/12 enca replicate
>
> On R1:
>
> R1(config)#policy-map SET-DSCP
> R1(config-pmap)#class class-default
> R1(config-pmap-c)#set dscp 46
> R1(config-pmap-c)#int e0/0
> R1(config-if)#service-policy output SET-DSCP
>
> Now I have both routers on VLAN 12 with a trunk between the two switches.
> SW1 has mls qos configured, SW2 does not so it leaves the marking alone. On
> port f0/12 I have a PC with wireshark. When I send pings from R1 to R2 they
> have DSCP 46. When the packets reach SW2 over the trunk they have DSCP46 and
> COS 5. SW1 set this without any mappings configured. The mappings are
> default.
>
> SW1#sho mls qos map dscp-co
> Dscp-cos map:
> d1 : d2 0 1 2 3 4 5 6 7 8 9
> ---------------------------------------
> 0 : 00 00 00 00 00 00 00 00 01 01
> 1 : 01 01 01 01 01 01 02 02 02 02
> 2 : 02 02 02 02 03 03 03 03 03 03
> 3 : 03 03 04 04 04 04 04 04 04 04
> 4 : 05 05 05 05 05 05 05 05 06 06
> 5 : 06 06 06 06 06 06 07 07 07 07
> 6 : 07 07 07 07
> SW1#
>
> If you want the packet capture, I can unicast it to you. I don't think the
> list accepts attachments.
>
> Bryan Bartik
> CCIE #23707, CCNP
> Sr. Support Engineer - IPexpert, Inc.
> URL: http://www.IPexpert.com
>
> On Sat, May 2, 2009 at 9:36 PM, Narbik Kocharians <narbikk_at_gmail.com>wrote:
>
>> It will NOT happen by just entering mls qos trust dscp. You need to
>> configure the map manually.
>>
>>
>> On Sat, May 2, 2009 at 8:25 PM, Bryan Bartik <bbartik_at_ipexpert.com>wrote:
>>
>>> Narbik,
>>>
>>> What do you mean "unless you change the mapping." There are default maps
>>> that will make the COS when you trust DSCP. I have tried it! :-)
>>>
>>>
>>> Bryan Bartik
>>> CCIE #23707, CCNP
>>> Sr. Support Engineer - IPexpert, Inc.
>>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>>
>>> On Sat, May 2, 2009 at 8:06 PM, Narbik Kocharians <narbikk_at_gmail.com>wrote:
>>>
>>>> *if I have interface with just mls qos trust dscp, if port receives
>>>> packet
>>>>
>>>> with for example DSCP 46, does it remark also COS field when it sends
>>>> packet
>>>> to anoter switch over trunk.*
>>>> *NO,* it does NOT, when you enter "mls qos trust dscp", it ONLY trusts
>>>> the
>>>> DSCP value and it has NOTHING to do with CoS. UNLESS YOU change the
>>>> mapping.
>>>> That was your question and this is your answer. If in doubt, please try
>>>> it,
>>>> IOS WILL ALWAYS TELL YOU THE TRUTH.
>>>>
>>>> *Does mls qos map policed-dscp remark DSCP and COS field or just DSCP?*
>>>>
>>>> *NO,* it does NOT touch COS field at all. Unless its configured to do
>>>> so.
>>>>
>>>> This is without twisting word around.
>>>> On Sat, May 2, 2009 at 1:40 PM, Petr Lapukhov
>>>> <petr_at_internetworkexpert.com>wrote:
>>>>
>>>> > Hi,
>>>> >
>>>> > In general, Catalyst switches implement "synchronous" marking logic:
>>>> > i.e. all potential
>>>> > QoS labels (L3,L2) are kept synchronized using the DSCP-to-CoS,
>>>> > CoS-to-DSCP and IP Prec-to-CoS
>>>> > global mapping tables. This is pretty natural if you think of
>>>> > "uniform" QoS marking model.
>>>> > In some cases it is possible to modify just one QoS marking point,
>>>> > keeping the other intact.
>>>> >
>>>> > See below for more details.
>>>> >
>>>> > > Does mls qos map policed-dscp remark DSCP and COS field or just
>>>> DSCP?
>>>> >
>>>> > Yes, CoS is modified according to the DSCP-to-CoS mapping table (in
>>>> > both 3550 and 3560).
>>>> > You may avoid CoS modification while policing in the 3550 model by
>>>> > using the configuration
>>>> > similar to the following:
>>>> >
>>>> > mls qos cos policy-map
>>>> > !
>>>> > policy-map POLICE_INBOUND
>>>> > class ICMP
>>>> > trust dscp
>>>> > set cos 2
>>>> > police 64000 16000 exceed-action policed-dscp-transmit
>>>> >
>>>> > Here you trust DSCP values and set CoS at the same time. Setting CoS
>>>> > directly in policy-map in only
>>>> > possible in the 3550 model when enabled by the special global-mode
>>>> > command. The 3560 does
>>>> > not provide such flexibility, and most of the time it is not needed.
>>>> >
>>>> > > if I have interface with just mls qos trust dscp, if port receives
>>>> packet
>>>> > > with for example DSCP 46, does it remark also COS field when it
>>>> sends
>>>> > packet
>>>> > > to anoter switch over trunk.
>>>> >
>>>> > Yes, by default CoS is modified according to the DSCP to CoS mapping
>>>> table.
>>>> > In the 3550 model you may avoid this behavior by enabling special CoS
>>>> > pass-thru mode:
>>>> >
>>>> > interface FastEthernet 0/4
>>>> > mls qos trust dscp pass-through cos
>>>> >
>>>> > (there is symmetric DSCP pass-thru mode, configured using the command
>>>> > "mls qos trust cos pass-through dscp")
>>>> >
>>>> > In the 3560 model, it is not possible to disable CoS rewrite. More
>>>> > than that, you have to set
>>>> > CoS values for non-IP packets by using the "set dscp" command, as
>>>> there is
>>>> > no "set cos" commad. Still, you can disable DSCP rewriting while
>>>> trusting
>>>> > CoS
>>>> > (mls qos trust cos) by entering the global command "no mls qos rewrite
>>>> ip
>>>> > dscp"
>>>> >
>>>> > HTH,
>>>> > --
>>>> > Petr Lapukhov, CCIE #16379 (R&S/Security/SP/Voice)
>>>> > petr_at_INE.com
>>>> >
>>>> > Internetwork Expert, Inc.
>>>> > http://www.INE.com <http://www.ine.com/> <http://www.ine.com/>
>>>> > Toll Free: 877-224-8987
>>>> > Outside US: 775-826-4344
>>>> >
>>>> > >
>>>> > >
>>>> > > Blogs and organic groups at http://www.ccie.net
>>>> > >
>>>> > >
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>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>>
>>>>
>>>> --
>>>> Narbik Kocharians
>>>> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
>>>> www.MicronicsTraining.com <http://www.micronicstraining.com/>
>>>> www.Net-Workbooks.com <http://www.net-workbooks.com/>
>>>> Sr. Technical Instructor
>>>>
>>>>
>>>> Blogs and organic groups at http://www.ccie.net
>>>>
>>>> _______________________________________________________________________
>>>> Subscription information may be found at:
>>>> http://www.groupstudy.com/list/CCIELab.html
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>>
>>>
>>
>>
>> --
>> Narbik Kocharians
>> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
>> www.MicronicsTraining.com
>> www.Net-Workbooks.com
>> Sr. Technical Instructor
>>
>
>
>
> --
> Bryan Bartik
> CCIE #23707, CCNP
> Sr. Support Engineer - IPexpert, Inc.
> URL: http://www.IPexpert.com
>

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