Interesting, especially given that both gold.garmin.com and silver.garmin.com are canonical (host)names for e3664.b.akamaiedge.net.
Also--if the app is calling home to Garmin via that exact IP address to authenticate, then that's poor programming on the app developer's part IMHO since what happens if the authentication server's IP address changes and/or the server that has that particular IP address assigned to it goes offline? That, or does someone know what hostname that IP address resolves to? Reverse DNS lookup on that IP address doesn't return a hostname...
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