External site not accessbile

JB 1 Reputation point
2021-04-01T21:14:19.937+00:00

We have a public facing server that is inaccessible from an internal network(DNS name: 123.net). Switching to a different network with different DNS 123.com there's no problem connecting or even accessing it outside our network. Server is using DNS 123.com.
Nslookup is pointed to correct ip address from a device that uses DNS123.net. Nslookup from internal network using DNS 123.com points to correct internal IP address.

Windows DHCP
Windows DHCP
Windows: A family of Microsoft operating systems that run across personal computers, tablets, laptops, phones, internet of things devices, self-contained mixed reality headsets, large collaboration screens, and other devices.DHCP: Dynamic Host Configuration Protocol (DHCP). A communications protocol that lets network administrators manage centrally and automate the assignment of Internet Protocol (IP) addresses in an organization's network.
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  1. Dave Patrick 426.1K Reputation points MVP
    2021-04-01T21:52:10.547+00:00

    Sounds like you might need a split brain deployment.
    https://learn.microsoft.com/en-us/windows-server/networking/dns/deploy/split-brain-dns-deployment

    --please don't forget to Accept as answer if the reply is helpful--

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  2. Candy Luo 12,656 Reputation points Microsoft Vendor
    2021-04-02T03:11:36.777+00:00

    Hi ,

    Based on my understanding, when your clients' DNS server point to 123.net then they cannot cannot access External website. Is that right? Please feel free to let me know if I have any misunderstanding.

    Did internal domain of 123.net has same name as external website? If yes and your external website name is www.123.net. Then the simple way is creating A record named www in the 123.net zone on the DC and give that record the website's IP address. Machines that query that DNS server then receives the correct response and be able to browse the website.

    For more details, you can refer to the following article:

    DNS Considerations in a Windows Environment with Identical Internal and External Domain Names

    Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

    Best Regards,
    Candy

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    1 person found this answer helpful.