<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[How to create a PTR Record rule?]]></title><description><![CDATA[<p dir="auto">I know you can create an ALIAS for one specific URL. But for example Teamviewer is using multiple subdomains: *.teamviewer.com<br />
How do I create a rule for something like that?</p>
<p dir="auto">Thanks for your help!</p>
]]></description><link>https://forum.netgate.com/topic/169380/how-to-create-a-ptr-record-rule</link><generator>RSS for Node</generator><lastBuildDate>Sat, 14 Mar 2026 02:12:08 GMT</lastBuildDate><atom:link href="https://forum.netgate.com/topic/169380.rss" rel="self" type="application/rss+xml"/><pubDate>Wed, 26 Jan 2022 10:24:42 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Reply to How to create a PTR Record rule? on Wed, 26 Jan 2022 13:36:34 GMT]]></title><description><![CDATA[<p dir="auto">@wellcomefit ASN is Autonomous System Number, this is what defines a group of IP prefixes..</p>
<p dir="auto">But teamviewer could be honestly pretty much anywhere on the planet from here.</p>
<p dir="auto"><a href="https://www.teamviewer.com/en-us/trust-center/faq/" target="_blank" rel="noopener noreferrer nofollow ugc">https://www.teamviewer.com/en-us/trust-center/faq/</a> with pretty much all the major CDNs</p>
<p dir="auto">So that pretty much wouldn't do you much good..  whitelisting *.teamviewer.com would be what you do when you use a proxy, not a firewall.  For that just open up port 5389.</p>
]]></description><link>https://forum.netgate.com/post/1021902</link><guid isPermaLink="true">https://forum.netgate.com/post/1021902</guid><dc:creator><![CDATA[johnpoz]]></dc:creator><pubDate>Wed, 26 Jan 2022 13:36:34 GMT</pubDate></item><item><title><![CDATA[Reply to How to create a PTR Record rule? on Wed, 26 Jan 2022 13:11:44 GMT]]></title><description><![CDATA[<p dir="auto"><a class="plugin-mentions-user plugin-mentions-a" href="/user/johnpoz">@<bdi>johnpoz</bdi></a> Thanks for your reply.</p>
<p dir="auto">I'm trying to whitelist anything.teamviewer.com for Port 5389 TCP/UDP.<br />
What is an ASN? I never used pfblocker. So this extension is capable of creating an allow list of all IP addresses which are owned by teamviewer?</p>
]]></description><link>https://forum.netgate.com/post/1021897</link><guid isPermaLink="true">https://forum.netgate.com/post/1021897</guid><dc:creator><![CDATA[somerino]]></dc:creator><pubDate>Wed, 26 Jan 2022 13:11:44 GMT</pubDate></item><item><title><![CDATA[Reply to How to create a PTR Record rule? on Wed, 26 Jan 2022 11:01:31 GMT]]></title><description><![CDATA[<p dir="auto">@wellcomefit your trying to block all access to anything.teamviewer.com ?  That would not really be possible with an alias.. How could you possible resolve any and all possible combinations of anything.domain.tld</p>
<p dir="auto">You could prevent anything.domain.tld resolving for the client if using pfsense as their dns, so they wouldn't know what IP to go to - if that your goal.  But there would be no way to populate a alias with IPs for anything.domain.tld - the combinations are almost infinite, etc.</p>
<p dir="auto">Are you trying to whitelist so clients could only go to something.teamviewer.com ?  Possible solution there would be to find out what ASN, ie the network they are using to host.. And then using pfblocker you could easy find all the ips/networks used by that ASN.. And then use that alias in an allow list, etc.</p>
]]></description><link>https://forum.netgate.com/post/1021879</link><guid isPermaLink="true">https://forum.netgate.com/post/1021879</guid><dc:creator><![CDATA[johnpoz]]></dc:creator><pubDate>Wed, 26 Jan 2022 11:01:31 GMT</pubDate></item></channel></rss>