[j-nsp] QFX5100 issues with IPv6 hashing

[Michael Loftis]

On Friday, April 17, 2015, Anton Yurchenko <ayurchenko at gmail.com> wrote:

> Hi All,
>
> I am seeing issues with QFX5100, hashing of IPv6 traffic over ECMP paths
> is very bad.
> In my case I have an ECMP over 3x40Gig links, and sending 180x10Mbit UDPv6
> flows over them. First 40G gets ~300mbit, second ~600 and third ~900.
> IPv4 hashing is fine ~5% variance in traffic levels.
>
> I have enabled hashing on L3/L4 and layer2-payload but no avail.
>
> It seems that protocol/ports are not taken into account at all. If I start
> traffic from just one IP with 30 flows, they will all end up on a single
> link.


You say 30 flows but are they differing at all? Even for v6 it looks at
Source IP, Dest IP, Proto, Source port, Dest port. If you traffic generator
doesn't vary the source port then each "flow" will look identical to the
hash algo.


>
> Seeing this on 13.2X51-D35.3 and 14.1X53-D25.2 releases.
>
> Here is my hashing config:
>
> load-balance {
>     indexed-load-balance;
> }
> hash-key {
>     family inet {
>         layer-3;
>         layer-4;
>     }
> }
> enhanced-hash-key {
>     hash-mode {
>         layer2-payload;
>     }
> }
>
> Wondering if anybody have seen something similar or have seen it working
> properly.
>
> Thanks!
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp
>


-- 

"Genius might be described as a supreme capacity for getting its possessors
into trouble of all kinds."
-- Samuel Butler