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QOS Config on 3560 Switch

Hey Guys,

I'm in the process of configuring QOS on a 3560 routing switch in a GOLD, SILVER, BRONZE priority type scenario.

Firstly,  I understand that this config will add a tag of "precedence 5" to a packet if it matches the "ACL_QOS_GOLD_In" access list. Question is does the router see this "precedence 5" tag and then sets the priority, or am I missing something in my config where at present it just sees the "precedence 5" and doesn’t act on it ?

Secondly, Since the "precedence 5" tag has already been added to the packets, do downstream routers see this tag and act accordingly or so I need to configure those is well ?

Here’s the coding

mls qos

interface GigabitEthernet0/1

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 52

switchport mode trunk

mls qos vlan-based

interface Vlan52

  ip address 10.x.x.x

  service-policy input PM_QOS_IN

class-map match-all CM_QOS_GOLD_In

   match access-group name ACL_QOS_GOLD_In

policy-map PM_QOS_IN

   class CM_QOS_GOLD_In

    set precedence 5

ip access-list extended ACL_QOS_GOLD_In

  permit ip host

  permit ip host

  permit ip host

  permit ip any host

Many Thanks

  • LAN Switching and Routing
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QOS Config on 3560 Switch

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QOS Config on 3560 Switch


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Whether your 3560 will act on your IPPrec 5 setting depends on its configuration.  "mls qos", alone, enables a default egress configuration, although don't recall what it uses, by default, for egress classification.

Regarding downstream devices, whether IPPrec 5 will be treated differently depends on those device configurations (and capabilities).  Often the default is no special treatment.

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