[j-nsp] Verifying Juniper ECMP

[John Neiberger]

​Another question: if a link in a ECMP "bundle" goes down and then comes
back up later, do things end up hashed and balanced the same way they were
prior to the link going down, or is there some amount of randomness to it?
If I check a certain flow and see that it is hashed to a particular link,
is it a fair bet that it was hashed to that same link prior to the link
going down?

Thanks,
John​


On Tue, Apr 15, 2014 at 12:07 PM, John Neiberger <jneiberger at gmail.com>wrote:

> Holy cow. I never would have figured that one out, and the two Juniper
> engineers I asked had no idea how to do it. I appreciate the help!
>
> Thanks,
> John
>
>
> On Tue, Apr 15, 2014 at 3:50 AM, Olivier Benghozi <
> olivier.benghozi at wifirst.fr> wrote:
>
>> Hi John,
>>
>> as usual with Juniper it's ridiculously overcomplicated, David Roy wrote
>> a fine article about that, at least for MX with DPC:
>>
>> http://www.junosandme.net/article-junos-load-balancing-part-3-troubleshooting-109382234.html
>>
>>
>> Olivier
>>
>> Le 15 avr. 2014 à 04:01, John Neiberger <jneiberger at gmail.com> a écrit :
>> > ​I know that ECMP is, by default, based on a hash of source and
>> destination
>> > IP address, and I know that we can see the available paths by doing
>> "show
>> > route forwarding-table destination <prefix>", but is there a way to
>> > determine which path a particular flow is using?
>> >
>> > For those of you familiar with Cisco, I'm looking for an equivalent to
>> > "show cef exact-route".
>>
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>
>
>