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Cisco 3850 qos

gfalk
Level 1
Level 1

Hey folks, undoubtedly stupid question but I'm failing badly at RTFM.

Have a fairly typical scenario where Cisco is remapping COS 5 to DSCP 40, when of course we're looking for DSCP 46.  In the 3750/6500/etc mls configuration, it's no big deal: mls qos map cos-dscp 0 8 16 24 32 46 48 56  and done.

Unfortunately on the 3850, I found reference in the documentation where it can be done, but not explicitly how to go do it.

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/qos/configuration_guide/b_qos_3se_3850_cg/b_qos_3se_3850_cg_chapter_011.html#ID942

I'm pretty confident I can just change the markings on the outbound interface but this kinda sucks as a solution :)  Would prefer just to handle it by default.

Many thanks!

3 Replies 3

Brandon Buffin
VIP Alumni
VIP Alumni

Appreciate the response!

What's happening is an inbound COS 5 hits the switch on a trunk port, gets converted by the system default to 40 DSCP, and then egresses on a L3 port.    The default conversion is to DSCP 40, and ideally there's a way to change the defaults as there was previously.

Went down the path of the AutoQoS bits but they're just default copy.  I can table-map it outbound, and might wind up doing that if I can't change it otherwise. 

Hi,

Just to test could you try this

!
class-map C5toD40 match-any
match cos 5
!
policy-map C5toD40
class C5toD40
set ip dscp 40
!
int x/x/x
service-policy input C5toD40
!  


Regards
Alex

Regards, Alex. Please rate useful posts.
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