# Attaching a QoS Profile to an Interface

You can attach a QoS profile to the base of an interface hierarchy, to a specific ATM VP or S-VLAN, or to a port type.

Tasks to attach a QoS profile include:

- Attaching a QoS Profile to a Base Interface
- Attaching a QoS Profile to an ATM VP
- Attaching a QoS Profile to an S-VLAN
- Attaching a QoS Profile to a Port Type

## Attaching a QoS Profile to a Base Interface

You can attach a QoS profile to an interface at the base of an interface hierarchy. Interface types below the attachment point cannot be referenced in the QoS profile.

To attach a profile to an interface:

1. Enter Interface Configuration mode for the interface.
   host1(config)#interface gigabitEthernet 2/0
2. Attach a QoS profile to the interface.
   host1(config-if)#qos-profile qosp-ethernet-queuing

## Attaching a QoS Profile to an ATM VP

You can associate a QoS profile with all the ports of a certain interface type.

You can attach a QoS profile to an ATM VP. The profile applies to all VCs in the VP; for example, the profile specifies the scheduler hierarchy of scheduler nodes and queues for all VCs, IP interfaces, and L2TP sessions stacked above the VP.

To attach a profile to an ATM VP:

1. Enter Interface Configuration mode for the interface.
   host1(config)#interface atm 1.0/1
2. Attach a QoS profile to the ATM VP.
   host1(config-if)#atm-vp 50 qos-profile qosp-vp-strictbw

If you attempt to modify the QoS profile attached to an ATM VP that contains nonbroadcast multiaccess (NBMA) or multipoint interfaces from profileA to profileB by using the atm-vp qos-profile command for a specific VP on that interface, the command is configured correctly and no error message is displayed in the CLI interface. However, the shaping rate on the interfaces that are part of the ATM VP is not properly updated with the shaping rate specified in profileB. Instead, the multipoint interfaces remain configured with the shaping rate set in profileA.

To modify the QoS profile currently attached to ATM VPs that contain NBMA or multipoint interfaces from another profile, you must first remove the QoS profile attached to the interfaces by using the no atm-vp qos-profile command in Interface Configuration mode, and then attach the new QoS profile to the interfaces by using the atm-vp qos-profile command. This restriction exists because the mungeing of QoS profiles does not occur correctly if any of the attributes of ATM VPs with multipoint interfaces are modified.

If you modify the QoS profile attached to a point-to-point ATM interface from profileA to profileB by using the qos-profile command (or the atm-vp qos-profile command for a specific VP on the ATM interface) in Interface Configuration mode, the shaping rate is correctly configured on the interface and is modified with the value specified in profileB.

To modify the QoS profile attached to an ATM VP that contains an NBMA or a multipoint interface from profileA to profileB, perform the following steps. These steps assume that profileA and profileB have been previously configured on the router.

1. Enter Interface Configuration mode for the ATM VP.
   host1(config)#interface atm 1/0
2. Remove the QoS profile, profileA, currently attached to the ATM VP that contains the NMBA interface.
   host1(config-if)#no atm-vp 1 qos-profile profileA
3. Attach the new QoS profile, profileB, that you want to be attached to the ATM VP that contains the NBMA interface.
   host1(config-if)#atm-vp 1 qos-profile profileB

## Attaching a QoS Profile to an S-VLAN

You can attach a QoS profile to the specified S-VLAN ID assigned to a VLAN subinterface that is configured over an Ethernet interface.

The profile applies to all S-VLANs and VLANs in the interface stack; for example, the profile specifies the hierarchy of scheduler nodes and queues for all VLANs, IP interfaces stacked above the S-VLAN. However, you do not have to configure VLAN subinterfaces over the S-VLAN before you attach the QoS profile to the S-VLAN.

1. Specify the Ethernet interface and create the VLAN.
   host1(config)#interface gigabitEthernet 3/0 host1(config-if)#encapsulation vlan host1(config-if)#interface gigabitEthernet 3/0.1
2. Specify the S-VLAN ID.
   host1(config-if)#svlan id 0 1
3. Attach the QoS profile to the S-VLAN.
   host1(config-if)#svlan 1 qos-profile qosp-svlan-strictbw

## Attaching a QoS Profile to a Port Type

By default, the router attaches a QoS port-type profile to all ATM, Ethernet, serial, or server ports. The port-type profile supplies QoS information for all forwarding interfaces stacked above all ports of the associated interface type.

Instead of using the default port-type profile, you can explicitly attach a QoS profile to a port. The QoS profile overrides the default QoS port-type profile. The QoS profile associates queue profiles, drop profiles, statistics profiles, and scheduler profiles with interface types, and it applies to all interfaces stacked above ports of the associated type.

To attach a QoS profile to a port type:

- Issue the qos-port-type-profile command from Global Configuration mode:
  host1(config)#qos-port-type-profile atm qos-profile strict-priority

  The interface type can be: atm, ethernet, lag, serial, or server-port.

  A profile attached to a port must specify a queue for each forwarding interface type in the best-effort traffic class.

To restore the default port-type:

- Issue the qos-port-type-profile command and specify the server-default QoS profile from Global Configuration mode:
  host1(config)#qos-port-type-profile server-port qos-profile server-default

#### Related Documentation

- Supported Interface Types for QoS Profiles
- Configuring a QoS Profile
- For information about attaching a QoS profile using Service Manager, see JunosE Broadband Access Configuration Guide
- atm-vp qos-profile
- atm vp-tunnel
- encapsulation vlan
- interface
- qos-port-type-profile
- qos-profile
- svlan id
- svlan qos-profile