Configuring Flow Exports on Juniper Routers

This section explains how to configure cflowd/J-Flow export on Juniper devices, enabling sampling and exporting flow records to a specific destination address.

Configuration Steps

To enable sampling and export flow records, use the following configuration:

forwarding-options { 
        sampling { 
            input { 
                family inet  { 
                    rate 100; 
                    run-length 9; 
                    max-packets-per-second 7000; 
                } 
            } 
            cflowd <destination address>{ 
                    port <port number>; 
                    source-address <source address>; 
                    version <version number>; 
                    no-local-dump; 
                    autonomous-system-type origin; 
            } 
        } 
}

To enable packet sampling on specific interface(s), follow these steps:

interfaces { 
    ge-1/3/0 { 
        vlan-tagging; 
        unit 101 { 
            vlan-id 101; 
            family inet { 
                sampling { 
                    input;   
                    output;   
                } 
                address 206.80.253.26/25;   
            } 
        } 
    } 
}

After completing the configuration, navigate to Menu > Flow Explorer and select the Event Source(s) and the associated Interface(s) from the drop-downs to view the active flow data.