Dns server issues

This topic contains 10 replies, has 6 voices, and was last updated by Avatar candie 2 years, 12 months ago.

Viewing 11 posts - 1 through 11 (of 11 total)
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    Opesy
    Member
    #166662

    I changed the ISP of my office, since then i cant contact the dns server,cant add clients to the domain, cant control users and computers on the domain..and dhcp is also not workng.
    Kindly assist to resolve this, i have been stranded for 2 weeks

    Avatar
    wullieb1
    Moderator
    #245513

    What DNS servers?

    Where was your DHCP server?

    Avatar
    Hirsch
    Member
    #391425

    Have you changed the settings in your modem or modem/router to point to your new ISP? It won’t automatically change by itself.

    Avatar
    purehacker
    Member
    #391538
    wullieb1;n507275 wrote:
    What DNS servers?

    Where was your DHCP server?

    Windows server 2012…it has the DNS server role and DHCP server..but non is working at the moment

    Avatar
    purehacker
    Member
    #391539
    JJKing;n507281 wrote:
    Have you changed the settings in your modem or modem/router to point to your new ISP? It won’t automatically change by itself.

    Its a fibre link and it is connected through static ip to my cisco wireless router…before the window server connects to one of the wireless router ports and other switches connect to another port on the switch.

    What setings are you refering to?

    Avatar
    Ossian
    Moderator
    #191417

    Changing ISP should not affect your internal network, so something is definitely wrong – if you got a new router, check it is the correct IP and does NOT have its own DHCP server (they often do, so you suddenly get 192.168 addresses instead of the correct ones).

    If it isn’t that:
    Start from the DC and confirm AD is working, Windows DNS is working (use the test option) and DHCP is authorised and running.
    Then check your DC can reach the internet (static network settings point to the new router etc) and the correct DNS forwarders are in place
    Then check DHCP is giving the correct details and work on to the clients.

    Avatar
    Hirsch
    Member
    #391426
    Opesy;n507286 wrote:
    Its a fibre link and it is connected through static ip to my cisco wireless router…before the window server connects to one of the wireless router ports and other switches connect to another port on the switch.

    What setings are you refering to?

    One line answers will not help us to help you resolve your issue. You have to describe your setup in detail or better, make a drawing of it even if you have to use MS Paint.

    If you do not understand what modem settings I am referring to then it may be a time saving idea to hire a professional IT consultant to change or check the modem settings. You will, at a minimum, have to change the credentials that you connect to the ISP with. Modem reboot may also be required. However since you mention a Cisco, it may require changing the settings by an SSH TELNET session. We don’t know what you have except a Cisco wireless router (do it have the modem) and Windows 2012 Server setup in a Domain.

    To paraphrase a moderator on the site (I’ve been reading), my car is not working, it is a Ford. What is wrong and how can I fix it? With that information can you help me get my car working again?

    Finally, disconnect the 2012 Server from the Cisco ports and plug it into one of the switches you have. This then isolates the Domain and all the devices from the Cisco and any possible interferences. It also means, if you have Gigabit switches, that your Domain is running at Gigabit speed. If the Cisco has 100Mbps ports and you plug the Server into that then everything that needs Domain resources will be connecting at the slower speed. We are having to GUESS about this because so far all we know is that you have a Ford (sic).

    Cisco model
    Switch(s) make & model
    Network drawing with the essential devices shown and how they are connected. Visio would be best but MS Paint will suffice.

    Avatar
    purehacker
    Member
    #391540
    Ossian;n507287 wrote:
    Changing ISP should not affect your internal network, so something is definitely wrong – if you got a new router, check it is the correct IP and does NOT have its own DHCP server (they often do, so you suddenly get 192.168 addresses instead of the correct ones).

    If it isn’t that:
    Start from the DC and confirm AD is working, Windows DNS is working (use the test option) and DHCP is authorised and running.
    Then check your DC can reach the internet (static network settings point to the new router etc) and the correct DNS forwarders are in place
    Then check DHCP is giving the correct details and work on to the clients.

    this is the output i got from testing AS
    Microsoft Windows [Version 6.3.9600]
    (c) 2013 Microsoft Corporation. All rights reserved.

    C:UsersAdministrator>dcdiag /test:replications

    Directory Server Diagnosis

    Performing initial setup:
    Trying to find home server…
    Home Server = BUSINESS
    * Identified AD Forest.
    Done gathering initial info.

    Doing initial required tests

    Testing server: Default-First-Site-NameBUSINESS
    Starting test: Connectivity
    ……………………. BUSINESS passed test Connectivity

    Doing primary tests

    Testing server: Default-First-Site-NameBUSINESS
    Starting test: Replications
    ……………………. BUSINESS passed test Replications

    Running partition tests on : ForestDnsZones

    Running partition tests on : DomainDnsZones

    Running partition tests on : Schema

    Running partition tests on : Configuration

    Running partition tests on : marandmor

    Running enterprise tests on : marandmor.local

    Result from running NSLOOKUP

    C:UsersAdministrator>NSLOOKUP
    Default Server: business.marandmor.local
    Address: 192.168.1.2

    > SERVER 192.168.1.2
    Server: [192.168.1.2]
    Address: 192.168.1.2

    *** 192.168.1.2 can’t find SERVER: Non-existent domain

    Result from TESTING DHCP

    C:UsersAdministrator>netsh dhcp server show server

    The current server is BUSINESS.marandmor.local with Ip Address = 192.168.1.2

    What can i be doing wrong

    Avatar
    Ossian
    Moderator
    #191418

    I really don’t know because I don’t know how your network should be set up.

    Keep it simple:
    On the DC (which OS is it)?
    Check all AD, DNS and DHCP services are running
    Check you can ping the router (and intermediate managed devices)
    Check you can ping externally by IP and Name

    If you can do all of that, AD and the DC are probably in good shape

    Avatar
    Hirsch
    Member
    #391427

    If this happened from the ISP change then I would suggest isolating the Domain from the Cisco. That is, unplug it so you can be sure there is zero interference coming from the Cisco. For all we know the new ISP may have provided the Cisco and it is not configured to work with an AD Domain. Once you have isolated the Domain, reboot the Domain Controller and then see what happens. Check the DHCP has not be de-authorised.
    Check that DNS Forwarders have been changed to represent the new ISP or point them to 8.8.8.8 and 8.8.4.4 (Google). This will obviously not work while you have the Cisco disconnected.
    You appear to have 2 issues. The ISP and Cisco config, which you seem reluctant to tell us about, and your AD possibly not working.
    This is the second time I have asked for a drawing of your setup, there will not be a third. Remember it is you that has the problem asking the members of this site for help. You MUST provide the information for that help to be beneficial. You need to help us if we are to help you. After 2 weeks I would have brought in an outside Professional IT Consultant, in fact I would have been on this site after 2 hours offline.

    I have seen these guys do a Scottie as in Captain Kirk, “Scottie, you’re a miracle worker”, once they get the network setup information that is required. (Was necessary to include since I have been referring to The Cisco from Deep Space 9 the last post or two :mrgreen: )

    Avatar
    candie
    Member
    #391563

    I share you a link regarding the above topic: https://technet.microsoft.com/en-us/library/cc731991(v=ws.11).aspx

    If you are unable to solve issue, then you have to go Microsoft support center

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