[EX/QFX] Traffic shaping on aggregated interfaces

Summary:

Junos implements Shaping-rate on an interface manner. An AE interface can operate in two modes: Scale and Replication modes.

Symptoms:

Consider the aggregated interface ae0 with four member links: ge-0/0/0, ge-0/0/1, ge-0/0/2 and ge-0/0/3.

Consider a shaping rate of 4Mbps applied on the ae0 interface with the following command:

class-of-service {
interfaces {
ae0 {
shaping-rate 4m;
}
}
}

With the above configuration and with the default mode (Scale), 4Mbps of traffic will be split it into the children interface, making the 4mbs divide into the children interfaces. 4mbs/3 interfaces.

Solution:

Junos implements Shaping-rate on an interface manner. An AE interface can operate in two modes: Scale and Replication modes.

The scale mode is also referred to as an equal division mode, so shaping-rate on AE interface will be divided equally to member links. If an AE interface has shaping-rate of 8m, then each member interface will have 4m shaping-rate.
The replication mode means each member link has the same shaping-rate as AE interface. If an AE interface has shaping-rate of 8m, then each member interface will have 8m shaping-rate.

By default, AE interface is running on Scale Mode.

The shaping-rate can be applied at the aggregate interface. However, check and keep in mind that aggregate interface will use the scale mode as default but it can be changed.

To change the AE shaping-rate mode, use member-link-schedule knob.

jnpr@R1-RE0# set class-of-service interfaces ae0 member-link-scheduler ?

Possible completions:

replicate Copy scheduler parameters from aggregate interface <---

scale Scale scheduler parameters on aggregate interface

Modification History:

5/11/2020: Updated solution to provide more clarity.

Knowledge Base