[c-nsp] MPLS EXP label imposition

[Oliver Boehmer (oboehmer)]

I haven't tried, but it should work by setting precedence via a
route-map applied via "ip local policy" and 

route-map FOO
 match ip address <acl>
 set ip precedence 3

I think in 12.3 and later, you can also use "set" commands in outbound
policy-maps, but this could get messy as you usually don't want to do
any fancy packet marking on your outbound policy-maps, only
classification and queuing..

	oli


Aly, Yasser <mailto:Yasser.Aly at getronics.com> wrote on Saturday,
September 10, 2005 10:10 PM:

> Oliver,
> 
>   Is it possible to set IP precedence (or MPLS-Exp)  for locally
> generated traffic. For example if you would like to set MPLS-EXP
> value to 3 for locally generated Telnet traffic. How this can be
> acheived?   
> 
> Regards,
> Yasser
> 
> ________________________________
> 
> From: cisco-nsp-bounces at puck.nether.net on behalf of Oliver Boehmer
> (oboehmer) 
> Sent: Sat 9/10/2005 7:00 PM
> To: Aly, Yasser; Merlin Gillespie; cisco-nsp at puck.nether.net
> Subject: RE: [c-nsp] MPLS EXP label imposition
> 
> 
> 
> Yasser,
> 
> behavior for locally generated traffic is identical, so if a routing
> protocol sets precedence 6 on its IP packets, the MPLS-EXP bits are
> set 
> accordingly upon label imposition.
> 
>         oli
> 
> Aly, Yasser <mailto:Yasser.Aly at getronics.com> wrote on Saturday,
> September 10, 2005 5:34 PM:
> 
>> Hi Oliver,
>> 
>>  I wonder how traffic locally generated by a router is treated in
>> terms of setting MPLS EXP value according to the type of traffic
>> (For example: Telnet from within a router, routing updates, and so
>> forth). 
>> 
>> How to set MPLS EXP value for locally generated traffic inside a
>> router. 
>> 
>> Regards,
>> Yasser
>> 
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net
>> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Oliver
>> Boehmer (oboehmer) Sent: Thursday, September 08, 2005 6:38 PM
>> To: Merlin Gillespie; cisco-nsp at puck.nether.net
>> Subject: RE: [c-nsp] MPLS EXP label imposition
>> 
>> Merlin Gillespie <> wrote on Thursday, September 08, 2005 4:09 PM:
>> 
>>> Following reading:
>>> http://www.cisco.com/warp/public/cc/pd/iosw/tech/mpotc_qp.htm
>>> 
>>> The following passage was brought to my attention:
>>> 
>>> By default, Cisco IOS(r) Software copies the three most significant
>>> bits of the DiffServ code point (DSCP) or the IP precedence of the
>>> IP packet to the EXP field in the MPLS shim header.
>>> 
>>> There is not much reference to this feature outside of the prior
>>> mentioned document. Can someone confirm that this is the default
>>> behaviour.
>> 
>> Yes, it is (I figure it is in most MPLS devices).
>> 
>>> If it is the default behaviour whether there is a global
>>> configuration to prevent this from happening.
>>> Or, if the only way to prevent this from happening is to manually
>>> rewrite all precedence bits to 0.
>> 
>> You can use the "MPLS DiffServ Tunneling Modes" feature
>> 
>
(http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newf
>> t/122t/122t13/ftdtmode.htm) and overwrite this with an appropriate
>> policy-map with "set mpls experimental 0" applied on the ingress
>> interface.. 
>> 
>>       oli
>> 
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