IOS new versions and network load

Jean-Francois Mezei jfmezei_nanog at
Mon Sep 18 17:11:22 UTC 2017

On 2017-09-18 08:48, Mike Hammett wrote:

> It looks very difficult to manage, given the DNS TXT records and domain search fields. If it was as simple as entering the supported IP ranges, it'd be a lot easier to implement. 

I would have to read the stuff again, but my understanding is:

caching server starts.
caching server registers with Apple, gives it its local IP, as well as
the IP ranges that it manages.

When a client wants something, it first reaches out to an Apple server.
That server decides which content server is nearest to the client, and
if there is a caching server in the same network, will give the client
the IP address to access that local caching server. (and this is where
there is NAT friendliness , as other have pointed out, designed mostlty
for enterprise).

The business about TXT records is to allow real IPs with multiple ranges
to be used. I *assume* that it is the caching server which reads those
records upon startup and then transmits it to Apple when it "logs in" as
a caching server. You can have up to 24 chained TXT records to list all
the IP blocks you can service.

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