[c-nsp] Troubleshooting ECMP/bundling issue (5-tuple black holing)

[adamv0025 at netconsultings.com]

> Lukas Tribus
> Sent: Thursday, March 09, 2017 11:30 AM
> 
> Hey guys,
> 
> 
> troubleshooting routing issues on paths external to our network that lead
to
> blackholing of specific 5-tuple combinations here, very likely due to
> ECMP/Bundling issues (we are link is up/up and used for load-balancing,
but
> cannot actually transmit or receive traffic, therefor dropping those
packets
> on the floor).
> 
> 
> Now, this happened a few times over the years, and I am wondering if you
> guys have any suggestions or tools that you use in those cases, other than
> tcpdump'ing at both ends, generating thousands of 5-tuple combinations and
> then analyzing them in wireshark.
> 
> Also, after obtaining a list of affected and unaffected 5-tuples, any
particular
> easy way to find out how this is getting hashed, so that we could find the
> likely number of bundle members (this could be very useful multiple
> interconnection and parties are involved).
> 
> 
Hey Lukas,

Different platforms have different possibilities to examine the hashing,
what platforms are you using?

adam


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