[c-nsp] mpls and etherchannel

Mark Tinka mark.tinka at seacom.mu
Fri Apr 22 09:31:33 EDT 2016

On 22/Apr/16 15:22, Adam Vitkovsky wrote:

> I was meant to ask when you mentioned it for the first time, how can one enable per-packet load-sharing in junos?
> I mean the per-flow is enabled with keyword: "per-packet" is there an option "per-packet-for-real" ? :)

You do it at the LAG port level:

tinka at lab# show interfaces ae2
encapsulation flexible-ethernet-services;
*aggregated-ether-options {**
**    load-balance {**
**        per-packet;**
*    }
    link-speed 10g;
    lacp {

Per-packet load balancing is one of two options; the other being "adaptive".

Adaptive was meant to fix the actual problem we are using per-packet to
solve, which is cases where spray of packets across the member links is
unequal. The adaptive mode was developed to dynamically realize and fix
this. Unfortunately, it doesn't work when the payload does not lend
itself well to LACP hashing.

So per-packet mode to the rescue.

By the way, only supported on routers (confirmed on MX Trio, as it's all
we have). Not supported on the EX switches (which doesn't matter, as
those do a good job of LACP hashing, since the payload is predictable).

I've asked Cisco to develop a similar capability, as it would make a
world of difference in our environment, technically and commercially.
More so for IOS XR, as per-packet is not supported at all on IOS XR
platforms, which, I feel, is bad form. Vendors need to allow their
customers some rope with which to hang themselves - I mean, they gave us
stateless ACL's, so :-)...


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