help with diagnosing traffic blackhole to / from select akamai ranges?

Thu Jan 9 18:52:40 UTC 2020

Good afternoon,

we have a downstream customer originating a more specific /24 prefix, and when they do so, traffic sourced from that /24 prefix to at least a subset of akamai ranges (at minimum the 184.27.24.0/22 block at this time) are getting blackholed somewhere along the path either to or from, but i’m not sure how best to go about troubleshooting or getting assistance with diagnosing where the problem may be.

from a device in the offending IP block I cannot ping or curl to www.akamai.com <http://www.akamai.com/> that resolves to 184.27.25.72, however from an IP outside the /24 specific prefix but still in their supernet range I am able to ping and get an HTTP 301 redirect response.  Some other akamai prefixes like 23.73.0.0/20 seem to work without issue from what I can tell thus far.  If the /24 prefix is removed, all works as expected via their covering announcement (which does return via their primary provider, as we are generally a backup path for their larger block).

Any guidance the community can share as to how to go about trying to resolve I would greatly appreciate — this is the first time i’ve had to trace down a [seemingly random] reachability issue like this.  Connectivity to other services seem ok from what I can gather so far, even to some other akamai ranges.  from looking glass perspective it looks like the route is being accepted properly by our upstreams and other large providers like NTT, etc.  I did send an email to noc at akamai.com <mailto:noc at akamai.com> but not sure that is the appropriate way to reach out for assistance or not, since we nor our downstream customer are direct customers or peers of theirs.

Thanks,

Will McLendon
wimclend at gmail.com <mailto:wimclend at gmail.com>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20200109/e53becce/attachment.html>