• I have an Android device (Minix M5) that I handed to a customer
  • The device only does outbound connections, so no inbound traffic
  • The customer confirmed that s/he opened up the ports necessary for the outbound communication
  • The customer has however blocked a lot of sites (including google.com)
  • I rather not give the customer a list with IPs to whitelist, since this might change over time


The device can't access my services due to the firewall.


  • Does the blocks on the websites trump the the opening of the ports?

I thought it was the other way around (= opening the ports would give the device access to any outbound communication).

What's the potential solutions for this? Could the customer give a certain IP free outbound traffic?

  • It would probably help quite a bit to know the vendor of the firewall being used. Generally though web filtering trumps open ports. If someone can get to yahoo, but not google then port 80 would be open allowing yahoo, and web filtering still kicks in and blocks google. – JekwA Jun 9 '15 at 18:53
  • Since your IPs may change, does your domain name change? – KDEx Jun 10 '15 at 3:03
  • Thanks for the prompt replies! @JekwA: I'll try to get more info regarding the vendor of the firewall. – daxro Jun 10 '15 at 5:21
  • @Morgoroth Yes, they may change. But even if they wouldn't change and we would forward that domain to another domain, the firewall would still block it, right? – daxro Jun 10 '15 at 5:24
  • It really depends how the firewall is configured. The firewall admin can simply create a new rule to allow outbound traffic for the ports you mentioned for the IP of your android device. – ρss Jun 10 '15 at 11:43

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