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Windows DNS Issue

Posted by AYY21 2022-08-10T17:06:10Z
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DNS

Hello,

Both our internal and external Domain are the same in the format domainname.com.

While everything is working fine, we are having trouble accessing our website from inside of our network (its working from the outside).

We have added additional A record in the Forward Lookup Zone. This had no impact and did not resolve the issue.

We then added another A record with www Host. So the FQDN is now www.domainname.com Opens a new window. After this was added, we were able to access the website with the full URL www.domainname.com Opens a new window. However, still can't access it without the www.

Can someone advise where we have gone wrong?

Thanks in advance.

Pepper graySpice (14) Reply (15)
User: Amelia Y
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15 Replies

  • Welcome!

    This is an old issue, and it's been brought up several times.

    You're not supposed to name your AD domain, the same as your public domain. Given that renaming your internal AD is, let's just say "challenging"...  In short, you can't fix it.

    I've heard of a suggestion where you create a web server on your primary domain controller, and redirect it to www.<your Opens a new window Opens a new window domain name>, but I don't know if that's still recommended (I think it causes other issues), and it's not recommended to setup a webserver on your PDC (because it may be used for other things).

    Pepper graySpice (3) flagReport
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  • Welcome to the Community. Its not the issue with your internal domain but external. You would need to add CNAME which points domain.com to www.domain.com Opens a new window in your DNS hosting provider.

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  • I'm starting to think that these split DNS issues for websites can all be solved with an a record for "*" in the domain.com forward lookup zone (internal AD DNS server) with the ipaddress of the web hosting server. But i don't have the right environment to test it just now.

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  • I ran into something similar. The problem came about that I couldn't get to a website without using www in front of it from internally. There is no way to assign a record that will get you to the website without the www internally. I checked with our DNS host. It wouldn't allow me to create the record I need and that is the way the system is currently designed even though the use of www by default is no longer used in most cases anymore. Didn't find a way around it, but it wasn't our primary link to the website so didn't have to pursue it.

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  • This is such an old topic. Please google DNS split brain and you will find your answer. If you are a novice I recommend you to watch itfreetraining videos in YouTube. The creator has uploaded amazing didactic videos that are perfect for anyone wanting to learn very important IT concepts.

    Sorry I cannot give you a straight answer right now.

    Good luck.

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  • Viyer7 wrote:

    This is such an old topic. Please google DNS split brain and you will find your answer. If you are a novice I recommend you to watch itfreetraining videos in YouTube. The creator has uploaded amazing didactic videos that are perfect for anyone wanting to learn very important IT concepts.

    Sorry I cannot give you a straight answer right now.

    Good luck.

    Looks to me as to be a totally different issue. Not talking about accessing a public vs. private website with the same name. Not to mention it goes back to the name resolution not working when not using www. 

    Pepper graySpice (2) flagReport
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  • Your domain name is going to resolve to your domain controllers. I don't think there's a way around this issue with the split-brain setup. On the plus side your setup with services like O365 will be a little less complicated.

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  • @craigsmith  Everyone replying here is under the assumption that the domain's names ARE the same. The OP has not corrected them and he was kind of vague on his explanation. If they are the same then this is a "classic" DNS slipt brain issue. If they are not the same then he has some IP somewhere misconfigured. 

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  • no, Viyer7​, it isn't that simple. You still are missing the issue. He is not trying to connect to a website on site. It won't allow them to go to the public website without using www in front of the domain when trying to connect to the website. Split brain as Nate6203​ and I have pointed out doesn't address that issue. The only way around this is if you have a subdomain as the website as in web.domain.com instead of just domain.com. I ran into this and it's not something that is fixable by DNS records. Without www.doman.com Opens a new window you can't get to the public website from inside as domain.com will direct/resolve you to the PDCs which don't or shouldn't have a website on them. Basically you just have to tell users to use www.domain.com Opens a new window to get to the website instead of just typing in domain.com.

    Pepper graySpice (1) flagReport
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  • Viyer7 wrote:

    @craigsmith  Everyone replying here is under the assumption that the domain's names ARE the same. The OP has not corrected them and he was kind of vague on his explanation. If they are the same then this is a "classic" DNS slipt brain issue. If they are not the same then he has some IP somewhere misconfigured. 

    No it's not split brain DNS. That phrase refers to intentionally providing different results internally and externally for the same domain. It's called split brain as the server needs to respond differently based on who asks - a split brain. Typically this was done using sperate servers on windows, but now ms dns server supports policies like bind. See https://docs.microsoft.com/en-us/windows-server/networking/dns/deploy/split-brain-dns-deployment#bkm... Opens a new window

    The OP wants exactly the opposite - they want the same result internally as externally. They basically have a problem of using their external DNS domain name as their AD domain name. not split brain dns.

    Pepper graySpice (1) flagReport
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  • Okay, okay, okay.. please stop making assumptions. You guys are trying to make sense of something based on a very vague description by the OP. First of all let's read again:
    1. Both our internal and external Domain are the same in the format domainname.com

    He said "format" he never specified if they ARE the same. I guess he is trying to say that there are not subdomains in the "format"

    2. While everything is working fine, we are having trouble accessing our website from inside of our network (its working from the outside).

    He is not clarifying "WHERE" is this website hosted - Is it hosted on-prem or on a 3rd party hosting? - BIG difference depending on the answer.

    3. We have added additional A record in the Forward Lookup Zone.

    This is useless unless specifies "WHERE" he added the record but again it will depend how point No.2 is answered

    I'm sorry but is pointless for me to continue the discussion until these basic questions are clarified.

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  • I guess you forgot to read this line:   " We then added another A record with www Host. So the FQDN is now www.domainname.com Opens a new window. After this was added, we were able to access the website with the full URL www.domainname.com Opens a new window. However, still can't access it without the www."

    No one is making assumptions. You didn't read the whole post very well. Split brain doesn't handle this issue. 

    Pepper graySpice (1) flagReport
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  • Well I guess you forgot to read your own post: "Not talking about accessing a public vs. private website with the same name"

    The adding of the www (which is basically a subdomain) doesn't automatically disqualified the split brain issue. In this case you are just trying to go around it.

    m@ttshaw, almost had the correct definition, except when he said " the server needs to respond differently based on who asks "  The "SPLIT" is because there's more than ONE server giving TWO different answers depending from "WHERE" you ask.

    Again this is pointless unless the OP clarifies the particular details of his DNS schema.

    I have spent more time that  I can on this.

    I wish you all good luck


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  • Well, If I missed any key point. That's my bad. I think you did, but hey we all read into things differently at times. There's a post about that under best practices that I put out there. It's been entertaining to see people purposely and accidentally doing exactly what I talk about in the post and seems to be happening here. You could be right with your assumptions but assuming is what it is. Seemed pretty obvious what the issue is and having been there I know what the original post is eluding to. But then again my experience could be tainting my point of view but it would seem others are in agreement with my assessment. But we could all be wrong and you might be right. Only time will tell.

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  • Viyer7​

    Viyer7 wrote:

    Okay, okay, okay.. please stop making assumptions. You guys are trying to make sense of something based on a very vague description by the OP. First of all let's read again:
    1. Both our internal and external Domain are the same in the format domainname.com

    He said "format" he never specified if they ARE the same. I guess he is trying to say that there are not subdomains in the "format"

    2. While everything is working fine, we are having trouble accessing our website from inside of our network (its working from the outside).

    He is not clarifying "WHERE" is this website hosted - Is it hosted on-prem or on a 3rd party hosting? - BIG difference depending on the answer.

    3. We have added additional A record in the Forward Lookup Zone.

    This is useless unless specifies "WHERE" he added the record but again it will depend how point No.2 is answered

    I'm sorry but is pointless for me to continue the discussion until these basic questions are clarified.

    "He said" "He is" - who is making assumptions now?

    " I'm sorry but is pointless for me to continue the discussion until these basic questions are clarified." and yet you replied again. rofl.

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