Example: Limiting Egress Traffic on an Interface Using Port Shaping for CoS

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Device R1 Using Only Class of Service

set interfaces ge-2/0/5 description to-Host
set interfaces ge-2/0/5 unit 0 family inet address 172.16.70.2/30
set interfaces ge-2/0/8 description to-R2
set interfaces ge-2/0/8 unit 0 family inet address 10.50.0.1/30
set interfaces lo0 unit 0 description looback-interface
set interfaces lo0 unit 0 family inet address 192.168.13.1/32
set class-of-service interfaces ge-2/0/8 shaping-rate 160k
set protocols ospf area 0.0.0.0 interface ge-2/0/5.0 passive
set protocols ospf area 0.0.0.0 interface lo0.0 passive
set protocols ospf area 0.0.0.0 interface ge-2/0/8.0

Device R1 Using Traffic Control Profiles and Class of Service

set interfaces ge-2/0/5 description to-Host
set interfaces ge-2/0/5 unit 0 family inet address 172.16.70.2/30
set interfaces ge-2/0/8 description to-R2
set interfaces ge-2/0/8 unit 0 family inet address 10.50.0.1/30
set interfaces lo0 unit 0 description looback-interface
set interfaces lo0 unit 0 family inet address 192.168.13.1/32
set class-of-service traffic-control-profiles output shaping-rate 160k
set class-of-service traffic-control-profiles output shaping-rate burst-size 30k
set class-of-service interfaces ge-2/0/8 output-traffic-control-profile output
set protocols ospf area 0.0.0.0 interface ge-2/0/5.0 passive
set protocols ospf area 0.0.0.0 interface lo0.0 passive
set protocols ospf area 0.0.0.0 interface ge-2/0/8.0

Device R2

set interfaces ge-2/0/7 description to-Host
set interfaces ge-2/0/7 unit 0 family inet address 172.16.80.2/30
set interfaces ge-2/0/8 description to-R1
set interfaces ge-2/0/8 unit 0 family inet address 10.50.0.2/30
set interfaces lo0 unit 0 description looback-interface
set interfaces lo0 unit 0 family inet address 192.168.14.1/32
set protocols ospf area 0.0.0.0 interface ge-2/0/7.0 passive
set protocols ospf area 0.0.0.0 interface lo0.0 passive
set protocols ospf area 0.0.0.0 interface ge-2/0/8.0

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode in the Junos OS CLI User Guide.

You can configure port shaping on network interfaces, aggregated Ethernet interfaces (also known as link aggregation groups (LAGs)), and loopback interfaces.

To configure Device R1:

1. Configure the device interfaces.

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   [edit]
   user@R1# set interfaces ge-2/0/5 description to-Host
   user@R1# set interfaces ge-2/0/5 unit 0 family inet address 172.16.70.2/30
   user@R1# set interfaces ge-2/0/8 description to-R2
   user@R1# set interfaces ge-2/0/8 unit 0 family inet address 10.50.0.1/30
   user@R1# set interfaces lo0 unit 0 description looback-interface
   user@R1# set interfaces lo0 unit 0 family inet address 192.168.13.1/32
   

2. Configure port shaping using only class of service.

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   [edit]
   user@R1# set class-of-service interfaces ge-2/0/8 shaping-rate 160k
   

3. Configure port shaping using traffic control profiles and class of service.

   Note:

   If you configure a fixed shaping rate, you can configure an optional burst size in bytes. If you configure the shaping rate as a percentage, the burst-size option is not allowed.

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   [edit]
   user@R1# set class-of-service traffic-control-profiles output shaping-rate 160k
   user@R1# set class-of-service traffic-control-profiles output shaping-rate burst-size 30k
   user@R1# set class-of-service interfaces ge-2/0/8 output-traffic-control-profile output
   

4. Configure OSPF.

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   [edit]
   user@R1# set protocols ospf area 0.0.0.0 interface ge-2/0/5.0 passive
   user@R1# set protocols ospf area 0.0.0.0 interface lo0.0 passive
   user@R1# set protocols ospf area 0.0.0.0 interface ge-2/0/8.0
   

Step-by-Step Procedure

To configure Device R2:

1. Configure the device interfaces.

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   [edit interfaces]
   set interfaces ge-2/0/7 description to-Host
   set interfaces ge-2/0/7 unit 0 family inet address 172.16.80.2/30
   set interfaces ge-2/0/8 description to-R1
   set interfaces ge-2/0/8 unit 0 family inet address 10.50.0.2/30
   set interfaces lo0 unit 0 description looback-interface
   set interfaces lo0 unit 0 family inet address 192.168.14.1/32
   

2. Configure OSPF.

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   [edit ]
   user@R1# set protocols ospf area 0.0.0.0 interface ge-2/0/7.0 passive
   user@R1# set protocols ospf area 0.0.0.0 interface lo0.0 passive
   user@R1# set protocols ospf area 0.0.0.0 interface ge-2/0/8.0
   

Results

From configuration mode, confirm your configuration by entering the show interfaces , show class-of-service, and show protocols ospf commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

Results for R1

user@R1# show interfaces
ge-2/0/5 {
    description to-Host;
    unit 0 {
        family inet {
            address 172.16.70.2/30;
        }
    }
}
ge-2/0/8 {
    description to-R2;
    unit 0 {
        family inet {
            address 10.50.0.1/30;
        }
    }
}
lo0 {
    unit 0 {
        description looback-interface;
        family inet {
            address 192.168.13.1/32;
        }
    }
}

Configuring Port Shaping Using only Class-of-Service

user@R1# show class-of-service
interfaces {
    ge-2/0/8 {
        shaping-rate 160k;
    }
}

Configuring Port Shaping Using Traffic Control Profiles and Class of Service

user@R1# show class-of-service
traffic-control-profiles {
    output {
        shaping-rate 160k burst-size 30k;
    }
}
interfaces {
    ge-2/0/8 {
        output-traffic-control-profile output;
    }
}

user@R1# show protocols ospf
area 0.0.0.0 {
    interface ge-2/0/5.0 {
        passive;
    }
    interface lo0.0 {
        passive;
    }
    interface ge-2/0/8.0;
}

If you are done configuring Device R1, enter commit from configuration mode.

Results for R2

user@R2# show interfaces
ge-2/0/7 {
    description to-Host;
    unit 0 {
        family inet {
            address 172.16.80.2/30;
        }
    }
}
ge-2/0/8 {
    description to-R1;
    unit 0 {
        family inet {
            address 10.50.0.2/30;
        }
    }
}
lo0 {
    unit 0 {
        description looback-interface;
        family inet {
            address 192.168.14.1/32;
        }
    }
}

user@R2# show protocols ospf
area 0.0.0.0 {
    interface ge-2/0/7.0 {
        passive;
    }
    interface lo0.0 {
        passive;
    }
    interface ge-2/0/8.0;
}

If you are done configuring Device R2, enter commit from configuration mode.

Purpose

Confirm that the interface counters are cleared.

Action

On Device R1, run the clear interfaces statistics ge-2/0/8 command to reset the interface statistics to 0.

user@R1> clear interfaces statistics ge-2/0/8

Purpose

Make sure that the traffic is rate-limited on the output interface (ge-2/0/8) on Device R1 by sending traffic into the network using the host connected to Device R1.

Action

1. Use a traffic generator to send several continuous streams of TCP packets with a source port of 80.

   The -s flag sets the source port. The -k flag causes the source port to remain steady at 80 instead of incrementing. The -d flag sets the packet size. The -c flag sets the packet count to be sent.

   The destination IP address of 172.16.80.1 represents a user that is downstream of Device R2. The user has requested a webpage from the host (the webserver emulated by the traffic generator), and the packets are sent in response to the request.

   Note:

   Remember in this example the port shaping has been set to 160 Kbps.

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   [user@host]#  hping 172.16.80.1 -s 80 -k -d 1500 -c 20 &
    hping 172.16.80.1 -s 80 -k -d 1500 -c 20 &
   .
   .
   .

2. On Device R1, check the interface counters by using the show interfaces extensive ge-2/0/8 command.

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   user@R1> show interfaces extensive ge-2/0/8
     Queue counters:       Queued packets  Transmitted packets      Dropped packets
       0                            17244                 3741            13470
       1                               13                   13                0
       2                                0                    0                0
       3                           149363               149363                0
     Queue number:         Mapped forwarding classes
       0                   best-effort
       1                   expedited-forwarding
       2                   assured-forwarding
       3                   network-control

Meaning

In the output you can see that 13470 packets have been dropped. These are the packets that exceeded the 160 Kbps shaping rate configured on ge-2/0/8.