[j-nsp] QFX5100 issues with IPv6 hashing

Anton Yurchenko ayurchenko at gmail.com
Mon Apr 27 12:57:35 EDT 2015



After more testing I think it was a problem with my testbed setup. After 
testing with a real traffic generator hashing looked good.


On 4/21/15 09:34, Anton Yurchenko wrote:
> Hi,
>
> I am using the -P option for iperf, it does vary source port dst port 
> is the same though. Normally (and with v4) traffic it results in good 
> hashing behavior.
>
> Thanks,
>
> On 4/18/15 07:21, Michael Loftis wrote:
>>
>>
>> On Friday, April 17, 2015, Anton Yurchenko <ayurchenko at gmail.com 
>> <mailto: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!
>>     _______________________________________________
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>>
>>
>>
>> -- 
>>
>> "Genius might be described as a supreme capacity for getting its 
>> possessors
>> into trouble of all kinds."
>> -- Samuel Butler
>>
>



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