DC Interelations



  • @scottalanmiller said

    Oh good point. Yes, it might be fine on its own. But we assume that it's not actively on the domain or that domain members are not aware of it, so it can't cause problem because it is isolated.

    NOT RELATED TO SITUATION AT HAND PER SE!!!

    If a DC is active, but DNS is down, would it still appear to the client? Or does the client indeed need DNS configured to see it?

    AKA, does the client send a "hey is there a domain controller out there" ... or is it all through the client DNS?



  • In the situation at hand, the DNS is not down that we know of. Just no one is using it.



  • @BRRABill said in Domain Controller Down (VM):

    @JaredBusch said in Domain Controller Down (VM):

    @scottalanmiller said in Domain Controller Down (VM):

    @BRRABill said in Domain Controller Down (VM):

    No he said he can't access it.

    He did?

    He did not. You are not crazy.

    He said
    "I'm assuming we must have had a domain syncing problem before this occurred, otherwise the other domain should have picked everything up as it is round robin. I attempted to disconnect my PC from the domain and reconnect. It claims there are no active directory controllers found."

    If he goes back with his DNS pointing to this DC and then tries again it would likely work just fine. But that would also be a bad thing in the situation he is in. just cluttering up unneeded AD changes to be cleaned up when he gets the other back online.



  • @scottalanmiller said in DC Interelations:

    In the situation at hand, the DNS is not down that we know of. Just no one is using it.

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem. Probably wouldn't just lose an IP in the middle of the day. Now, DNS being down, that would be much more likely. That would be easy to troubleshoot from an existing machine.

    Now, he did say that "I set a static IP on the computer I am on currently and can connect to the internet." but there are pieces missing from that. Did he also set a DNS like 8.8.8.8?

    And that is my question.

    If you are on a domain-joined machine, and you set your DNS to Google's DNS server, and then leave the domain and reboot ... will you be able to rejoin the domain?



  • @BRRABill said in DC Interelations:

    @scottalanmiller said in DC Interelations:

    In the situation at hand, the DNS is not down that we know of. Just no one is using it.

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem. Probably wouldn't just lose an IP in the middle of the day. Now, DNS being down, that would be much more likely. That would be easy to troubleshoot from an existing machine.

    No, it is a DHCP configration problem.



  • @BRRABill said in DC Interelations:

    Now, he did say that "I set a static IP on the computer I am on currently and can connect to the internet." but there are pieces missing from that. Did he also set a DNS like 8.8.8.8?

    And that is my question.

    If you are on a domain-joined machine, and you set your DNS to Google's DNS server, and then leave the domain and reboot ... will you be able to rejoin the domain?

    There is so much wrong with that statement I cannot even get in to it.



  • @JaredBusch said

    There is so much wrong with that statement I cannot even get in to it.

    And it's not even that long of a statement!



  • @BRRABill said in DC Interelations:

    If you are on a domain-joined machine, and you set your DNS to Google's DNS server, and then leave the domain and reboot ... will you be able to rejoin the domain?

    Most likely not. AD relies on DNS to do pretty much anything. If you don't have a local AD implementation then it doesn't know what IP address it should be directing to.



  • @BRRABill said in DC Interelations:

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem.

    If by "unlikely" you mean "almost certain."



  • @BRRABill said in DC Interelations:

    Now, DNS being down, that would be much more likely.

    If by "more likely" you mean, "not very likely but not actually impossible."



  • @BRRABill said in DC Interelations:

    @scottalanmiller said in DC Interelations:

    In the situation at hand, the DNS is not down that we know of. Just no one is using it.

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem. Probably wouldn't just lose an IP in the middle of the day. Now, DNS being down, that would be much more likely. That would be easy to troubleshoot from an existing machine.

    You could most certainly lose your IP address in the middle of the day... that's kind of how DHCP leases work. If you have a super short lease time (4 hours for instance) if you lose your DHCP server when the lease expires it has nowhere to get another lease from.



  • @coliver said in DC Interelations:

    @BRRABill said in DC Interelations:

    @scottalanmiller said in DC Interelations:

    In the situation at hand, the DNS is not down that we know of. Just no one is using it.

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem. Probably wouldn't just lose an IP in the middle of the day. Now, DNS being down, that would be much more likely. That would be easy to troubleshoot from an existing machine.

    You could most certainly lose your IP address in the middle of the day... that's kind of how DHCP leases work. If you have a super short lease time (4 hours for instance) if you lose your DHCP server when the lease expires it has nowhere to get another lease from.

    Pretty expected, actually.



  • @scottalanmiller said

    Pretty expected, actually.

    Most of ours here are all in the AM. Always just figured it was when the PC turned on.

    Sorry to have gummed up the other thread.



  • @scottalanmiller said in DC Interelations:

    @coliver said in DC Interelations:

    @BRRABill said in DC Interelations:

    @scottalanmiller said in DC Interelations:

    In the situation at hand, the DNS is not down that we know of. Just no one is using it.

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem. Probably wouldn't just lose an IP in the middle of the day. Now, DNS being down, that would be much more likely. That would be easy to troubleshoot from an existing machine.

    You could most certainly lose your IP address in the middle of the day... that's kind of how DHCP leases work. If you have a super short lease time (4 hours for instance) if you lose your DHCP server when the lease expires it has nowhere to get another lease from.

    Pretty expected, actually.

    Excuse my ignorance in these issues. (@JaredBusch you may want to look away.)

    Since he is going crazy, I assume everyone is down. You think all the DHCP leases all expired at the same time?



  • @BRRABill said in DC Interelations:

    @scottalanmiller said

    Pretty expected, actually.

    Most of ours here are all in the AM. Always just figured it was when the PC turned on.

    Sorry to have gummed up the other thread.

    Leases are all different times, PCs turn on at all different times. I'd guess most shops keep them on all the time. But reboot and lease schedules often come from patches, not people getting to the office.



  • @BRRABill said in DC Interelations:

    Since he is going crazy, I assume everyone is down. You think all the DHCP leases all expired at the same time?

    No, while not impossible, it's not very likely.



  • @BRRABill said in DC Interelations:

    @scottalanmiller said in DC Interelations:

    @coliver said in DC Interelations:

    @BRRABill said in DC Interelations:

    @scottalanmiller said in DC Interelations:

    In the situation at hand, the DNS is not down that we know of. Just no one is using it.

    So, a user could not connect to the Internet. Happening in the middle of the day, it's unlikely that is a DHCP problem. Probably wouldn't just lose an IP in the middle of the day. Now, DNS being down, that would be much more likely. That would be easy to troubleshoot from an existing machine.

    You could most certainly lose your IP address in the middle of the day... that's kind of how DHCP leases work. If you have a super short lease time (4 hours for instance) if you lose your DHCP server when the lease expires it has nowhere to get another lease from.

    Pretty expected, actually.

    Excuse my ignorance in these issues. (@JaredBusch you may want to look away.)

    Since he is going crazy, I assume everyone is down. You think all the DHCP leases all expired at the same time?

    His problem is DNS. But DNS is handed out by the DHCP server, which is the issue. I already said he could go hit every device and manually set DNS in the clients and it would work. but that is not resolving the issue.



  • @JaredBusch said

    His problem is DNS. But DNS is handed out by the DHCP server, which is the issue. I already said he could go hit every device and manually set DNS in the clients and it would work. but that is not resolving the issue.

    And all I was asking (perhaps unrelated to his issue, and again, sorry to muddy the waters) was that since people were suggesting he restore from backup, isn't that frowned upon if there is indeed still a working DC in his domain? I do know people who have done it and lived to tell the tale. (Considering you were a part of me finding out today that I've had a microphone in my laptop for 4 years now and didn't know, I bet you can guess who it was.)

    That's it.

    I know YOU are trying to get him to recreate the VM. I was only talking about restoring a DC from backup. Because it was mentioned.



  • @BRRABill said in DC Interelations:

    @JaredBusch said

    His problem is DNS. But DNS is handed out by the DHCP server, which is the issue. I already said he could go hit every device and manually set DNS in the clients and it would work. but that is not resolving the issue.

    And all I was asking (perhaps unrelated to his issue, and again, sorry to muddy the waters) was that since people were suggesting he restore from backup, isn't that frowned upon if there is indeed still a working DC in his domain? I do know people who have done it and lived to tell the tale. (Considering you were a part of me finding out today that I've had a microphone in my laptop for 4 years now and didn't know, I bet you can guess who it was.)

    That's it.

    I know YOU are trying to get him to recreate the VM. I was only talking about restoring a DC from backup. Because it was mentioned.

    Restoring a DC that is only a DC is stupid. you have the risks of replications, etc.

    But his DC is not just a DC. It is also the primary DNS server used inthe network as a whole and the DHCP server.

    The minor if any issues he you would see for restoring a DC are nothing compared to getting this all up and working.



  • @JaredBusch said

    The minor if any issues he you would see for restoring a DC are nothing compared to getting this all up and working.

    OK.

    When this unnamed person did it, there was a lot of stern talk about how dumb it was. (Even though it all worked out fine.)

    Glad to know it's not such a big deal.

    Carry on...



  • @BRRABill said in DC Interelations:

    @JaredBusch said

    The minor if any issues he you would see for restoring a DC are nothing compared to getting this all up and working.

    OK.

    When this unnamed person did it, there was a lot of stern talk about how dumb it was. (Even though it all worked out fine.)

    Glad to know it's not such a big deal.

    Carry on...

    It is not a best practice for valid reasons.

    But that does not mean that things do not work.


  • Banned

    @BRRABill said in DC Interelations:

    @JaredBusch said

    The minor if any issues he you would see for restoring a DC are nothing compared to getting this all up and working.

    OK.

    When this unnamed person did it, there was a lot of stern talk about how dumb it was. (Even though it all worked out fine.)

    Glad to know it's not such a big deal.

    Carry on...

    Is this me and that stupid exchange export from Hyper-V into XS that is being discussed here?



  • @DustinB3403 said in DC Interelations:

    @BRRABill said in DC Interelations:

    @JaredBusch said

    The minor if any issues he you would see for restoring a DC are nothing compared to getting this all up and working.

    OK.

    When this unnamed person did it, there was a lot of stern talk about how dumb it was. (Even though it all worked out fine.)

    Glad to know it's not such a big deal.

    Carry on...

    Is this me and that stupid exchange export from Hyper-V into XS that is being discussed here?

    No no, it was all me.



  • Oh, did I say that?



  • And yes, I really did not know my laptop had a microphone?

    Anyone else do anything dumb today?



  • @BRRABill said in DC Interelations:

    @DustinB3403 said in DC Interelations:

    @BRRABill said in DC Interelations:

    @JaredBusch said

    The minor if any issues he you would see for restoring a DC are nothing compared to getting this all up and working.

    OK.

    When this unnamed person did it, there was a lot of stern talk about how dumb it was. (Even though it all worked out fine.)

    Glad to know it's not such a big deal.

    Carry on...

    Is this me and that stupid exchange export from Hyper-V into XS that is being discussed here?

    No no, it was all me.

    So, not that anyone cares, but this is what happened:

    When I was doing a P2V of our DATA server, I wasn't thinking that it was also a DC. The P2V worked fine, then I was like ... oohhhh, maybe I shouldn't have done that.

    Obviously I should have demoted it first. And obviously I should have had all those roles on one server.

    But that's all in the past.

    LOOK A BIRD!



  • I don't want to confuse anyone in that other thread...

    But if, say, the port the host was plugged into went bad, the host and VMs would still be able to talk to each other right?



  • @BRRABill said in DC Interelations:

    I don't want to confuse anyone in that other thread...

    But if, say, the port the host was plugged into went bad, the host and VMs would still be able to talk to each other right?

    He would not be able to connect to any VM on that host.
    The fact that the vSphere console sees it hints that this isnot a problem. but it certainly is still possible if they had dedicated management networks. That is uncommon in this size though.


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