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<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I need to create a firewall rule for outgoing traffic from my network to the internet for services hosted in public clouds where the destination URL has multiple dynamic IPs (ie: an AWS S3 bucket, Outlook 365 in Azure, etc) which makes
a rule based on a destination FQDN troubling because each DNS query will provide a different IP every time. My possible solutions are:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<ol style="margin-top:0cm" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo1">Use a firewall rule using a Web URL filter, or application/content filtering (depending on the vendor) where I need to perform deep packet inspection to get the full destination URL
or detect the application (ie: email delivery to O365). When this method is used with most of the vendors, the process involves a MITM approach where the SSL Certificate presented to the client is one generated by the firewall with the root CA certificate
issued by the firewall as well.<o:p></o:p></li></ol>
<p class="MsoListParagraph"><o:p> </o:p></p>
<ol style="margin-top:0cm" start="2" type="1">
<li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo1">Set the destination IP of the rule the full list of possible ranges for the public cloud which could mean millions of IPs.<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any thoughts on security concerns with each of the approaches? Is it worth the potential decrease in security by using a non-trusted Root CA internally (even though we can install the certificate in the application/browser to force it to
trust it) vs. allowing access to destination IPs that are not necessary for this service but ensures uninterrupted encryption end-to-end?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Andres<o:p></o:p></p>
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