Configuring Modular QoS on Link Bundles

This chapter covers the following topics:

QoS on Link Bundles

A bundle is a group of one or more ports that are aggregated together and treated as a single link. The router supports Ethernet interfaces and VLAN interfaces (bundle sub-interfaces) bundles. All QoS features currently supported on physical interfaces, are also supported on all link bundle interfaces. Applying QoS on bundle members is not supported.

Load Balancing

Load balancing function is a forwarding mechanism to distribute traffic over multiple links based on Layer 3 routing information in the router. Per-destination load balancing isonly supported on the router, where the router is allowed to distribute packets over one of the links in the bundle. When the per-destination load balancing is enabled, all packets for a certain source-destination pair goes through the same link, though there are multiple links available. In other words, per-destination load balancing can ensure that packets for a certain source-destination pair could arrive in order.

Layer 3 Load Balancing on Link Bundles

Layer 3 load balancing for link bundles is done on Ethernet Flow Points (EFPs) and is based on the IPv4 source and destination addresses in the packet. When Layer 3 service-specific load balancing is configured, all egress bundles are load balanced based on the IPv4 source and destination addresses. When packets do not have IPv4 addresses, default load-balancing (based on the MAC SA/DA fields in the packet header) is used.

Configure QoS on Link Bundles

QoS is configured on link bundles in the same way that it is configured on individual interfaces.

Guidelines

  • When a QoS policy is applied on a bundle in the egress direction, it’s also applied at each member interface.

  • When a QoS policy is applied on a bundle (ingress direction), it’s replicated at each NPU core.

  • If a QoS policy is not applied to a bundle interface, both the ingress and egress traffic use the default queue of the per link member port.

  • The shape rate that is specified in the bundle policy-map is not an aggregate for all bundle members. The shape rate applied to the bundle depends on the load balancing of the links. For example, if a policy map with a shape rate of 10 Mbps is applied to a bundle with two member links, and if the traffic is always load-balanced to the same member link, then an overall rate of 10 Mbps applies to the bundle. However, if the traffic is load-balanced evenly between the two links, the overall shape rate for the bundle becomes 20 Mbps.

  • If a member is deleted from a bundle, the total bundle statistics changes because the statistics that belongs to the detached link is lost.

  • The QoS policy that is applied on bundle is inherited to all its member links and the reference bandwidth that is used to calculate shaper/bandwidth is applied as per the physical member interface bandwidth, and not the bundle as a whole.

Configuration Example

You have to accomplish the following to complete the QoS configuration on link bundles:


Note


The policy works only if it is applied on the ingress direction. The egress is supported on COS, DEI and MPLS exp marking. So the below policy may not work when it is applied on egress.


  1. Creating a class-map

  2. Creating a policy-map and specifying the respective class-map

  3. Specifying the action type for the traffic

    Refer Attach a Traffic Policy to an Interface for details on step 1, 2 and 3.

  4. Creating a link bundle

  5. Applying traffic policy to the link bundle


/* Configure Ether-Bundle and apply traffic policy */
Router(config)# interface Bundle-Ether 12000
Router(config-if)# mtu 9100
Router(config-if)# service-policy input ingress
Router(config-if)# service-policy output egress
Router(config-if)# ipv4 address 100.12.0.0 255.255.255.254
Router(config-if)# bundle maximum-active links 64
Router(config-if)# commit

Running Configuration

This example shows how a traffic policy is applied on an Ethernet link bundle. The policy is applied to all interfaces that are members of the Ethernet link bundle.


/* Policy-map */

policy-map ingress
 class inet4-classifier-af1
  set qos-group 1
 !
 class inet4-classifier-af2
  set qos-group 2
 !
 class inet4-classifier-af3
  set qos-group 3
 !
 class inet4-classifier-af4
  set qos-group 4
 !
 class inet4-classifier-be1
  set qos-group 5
 !
 class inet4-classifier-nc1
  set qos-group 6
 !
 class class-default
 !
 end-policy-map
!

/* Ether Bundle */
interface Bundle-Ether12000
 mtu 9100
 service-policy input ingress
 service-policy output egress
 ipv4 address 100.12.0.0 255.255.255.254
 load-interval 30
 flow ipv4 monitor FMM-V4 sampler SM ingress
 flow ipv6 monitor FMM-V6 sampler SM ingress
 flow mpls monitor FMM-MPLS sampler SM ingress
 ipv4 access-group IPV4ACL_101 ingress
 ipv6 access-group IPV6ACL_101 ingress
!

Verification

  • Verify that the bundle status is UP.

    
    router# show bundle bundle-ether 1200
    Wed Dec 16 19:55:49.974 PST
    
    Bundle-Ether12000
      Status:                                    Up
      Local links <active/standby/configured>:   35 / 0 / 35
      Local bandwidth <effective/available>:     3500000000 (3500000000) kbps
      MAC address (source):                      ea3b.745f.c4b0 (Chassis pool)
      Inter-chassis link:                        No
      Minimum active links / bandwidth:          1 / 1 kbps
      Maximum active links:                      64
      Wait while timer:                          2000 ms
      Load balancing:                            Default
      LACP:                                      Operational
        Flap suppression timer:                  Off
        Cisco extensions:                        Disabled
        Non-revertive:                           Disabled
      mLACP:                                     Not configured
      IPv4 BFD:                                  Not configured
    
      Port                  Device           State        Port ID         B/W, kbps
      --------------------  ---------------  -----------  --------------  ----------
      Hu0/4/0/0             Local            Active       0x8000, 0x0009   100000000
          Link is Active
      Hu0/4/0/1             Local            Active       0x8000, 0x000a   100000000
          Link is Active
    - - - 
    - - -
      Hu0/4/0/35            Local            Active       0x8000, 0x002b   100000000
          Link is Active
    
    
  • Verify the bundle statistics:

    
    router# show policy-map interface bundle-ether 12000 
    
    Bundle-Ether12000 input: ingress
    
    Class inet4-classifier-af1
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :          4647401962/21236124455654       26403040
        Transmitted         :          4647401962/21236124455654       26403040
        Total Dropped       :                   0/0                    0
    Class inet4-classifier-af2
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :          4502980177/20576584333939       25571493
        Transmitted         :          4502980177/20576584333939       25571493
        Total Dropped       :                   0/0                    0
    Class inet4-classifier-af3
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :          4647404125/21236213667880       26389086
        Transmitted         :          4647404125/21236213667880       26389086
        Total Dropped       :                   0/0                    0
    Class inet4-classifier-af4
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :          9291188840/42456120548683       52771168
        Transmitted         :          9291188840/42456120548683       52771168
        Total Dropped       :                   0/0                    0
    Class inet4-classifier-be1
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :          4647413429/21235847852686       26393414
        Transmitted         :          4647413429/21235847852686       26393414
        Total Dropped       :                   0/0                    0
    Class inet4-classifier-nc1
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :          9294887621/42473100149807       52778258
        Transmitted         :          9294887621/42473100149807       52778258
        Total Dropped       :                   0/0                    0
    
    Class class-default
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :                   0/0                    0
        Transmitted         :                   0/0                    0
        Total Dropped       :                   0/0                    0
    
    Bundle-Ether12000 output: egress
    
    Class c1
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :         16665494532/75878118942463       8760591
        Transmitted         :         16655834643/75834136022017       8760591
        Total Dropped       :             9659889/43982920446          0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 9659889/43982920446
    Class c2
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :         16665421959/75877849543188       8718687
        Transmitted         :         16665421959/75877849543188       8718687
        Total Dropped       :                   0/0                    0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 0/0
    Class c3
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :         16665247833/75877509455458       8703470
        Transmitted         :         16665187414/75877234624197       8703470
        Total Dropped       :               60419/274831261            0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 60419/274831261
    Class c4
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :         33330896131/151755393012945      17470745
        Transmitted         :         33330745421/151754709368565      17470745
        Total Dropped       :              150710/683644380            0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 150710/683644380
    Class c5
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :         16878910340/76849791869834       8833394
        Transmitted         :         16878849464/76849514633309       8833394
        Total Dropped       :               60876/277236525            0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 60876/277236525
    Class c6
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :         33330898844/151756094112925      17456785
        Transmitted         :         33330752668/151755427708382      17456785
        Total Dropped       :              146176/666404543            0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 146176/666404543
    Class c7
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :              244106/79922040             74
        Transmitted         :              244106/79922040             74
        Total Dropped       :                   0/0                    0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 0/0
    Class class-default
      Classification statistics          (packets/bytes)     (rate - kbps)
        Matched             :        267075066180/1215993441123215     139917482
        Transmitted         :        267075066180/1215993441123215     139917482
        Total Dropped       :                   0/0                    0
      Queueing statistics
        Queue ID                             : None (Bundle)
        Taildropped(packets/bytes)           : 0/0
    
    

Related Topics

Associated Commands

  • bundle maximu-active links

  • interface Bundle-Ether