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The Domain Name System (DNS) is a hierarchical, globally distributed system responsible for associating the name of a computer, service or other resource into an IP address for connecting to the Internet or a private network. Most prominently, it translates domain names to the numerical IP addresses needed for the purpose of computer services and devices worldwide.

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SBS2008 Server on a 1G network doesn't show on the network on all devices. All other computers, WIN7, WIN10, and 2012 Server Standard show all computers minus SBS2008. Any help why the SBS2008 doesn't show would be helpful. There aren't any login issues or DNS problems I'm aware of.
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I've just built 3 Raspbian stretch servers. They're used for nothing but NTP and DNS and had worked perfectly under wheezy. Now I'm seeing many errors in syslog that I have no clue how to resolve - they weren't there under the old OS. How can I resolve this? The OS is up to date with apt-get dist-upgrade

I'll attach my named.conf files and a portion of syslog:

I've already disabled ipv6 in /etc/sysctl.conf
# Disable IPv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

and then run sysctl -p

No effect on the issue at all.
Our Microsoft Exchange Server 2010 is for some reason using the highest number priority MX record before it uses the lowest number.  It continues to have problems sending out emails and the logs are showing its using the highest numbered record.  The problem with several of the domains we send email to is their highest number priority records

My interim fix has been entering a separate send connector for each of the domains have the problem.  I specify the send connector just for that email domain, and instead of using DNS lookup I enter the FQDN of the lowest priority number MX record into the Smart Host area.

Have had to do this for 3 domains now that have high priority number MX records pointing to mail servers that are not responsive.
Issue creating trust between two forests.  I have setup forwarders between DC's in DomainA and DC's in DomainB.  All DC's can ping each other as well as the domains.  I have created reverse lookup zones on both sides for the other domain as well with PTR records for the other side.  

While in DomainB I am able to create the two way trust in that domain only.

I then move over to DomainA to create the other half of the trust but I get the following error

The New Trust Wizard cannot continue because the specified domain cannot be contacted.

Either the domain does not exist, or network or other problems are preventing connection.

All ports are opened between the networks and all firewalls are turned off.  As I said I can ping servers from both sides using FQDN as well as the domain of each side.  I am stuck and getting lost in DNS as that is where I think the issue is I just am not sure where.
DNS issue

so i am new to DNS, here is my problem

we have a marketing site hosted, externally the site works perfect however lately internally when we hit the url we get page cannot be displayed, the fix is to go to our DNS servers and clear cache which works for about 30 minutes then it breaks again
Receiving error in event viewer:
    DCOM got error "2147944122" from the computer [IP] when attempting to activate server: {SID}
    EventID 1006
    Each domain controller is receiving 100 per day (probably more)

Our environment:
- 3x 2008 R2domain controllers running at 2008 level

We have recently:
- Added a 2016 domain controller (we just start on journey to upgrade to 2016) which has been promo'd and DNS configured/no DHCP yet
- Turned on scavenging in DNS (discovered it was never set - had records over 10 years old)

Error shows up on all four domain controllers (new and old).  Everything seem so be working and am unsure when the error started on the servers.

All help gratefully received as scratching head.
Hi Experts

I'm doing DNS migration from one provider to another and I know @ refers to root domain.

I see an - A record that states as * too.

1What does * refers to in DNS record? I have attached screenshot.
There are two * records.
1 is * that pointing to IP address as shown above and the other is *.domain.com that also pointing to same IP.

My company will be moving in a few weeks and as part of the move, I'll be phasing out two old domain controllers. Before I do that, I plan to move DHCP services to the new DCs. I tried to set this up while at our current location, but then realized that the IP Helper on our switch points to the old domain and this was (likely) preventing our new one from responding to and distributing addresses.

So my question is - if I just set up the new office with the IP helper for my VLANs on new switch hardware pointing to the new DC/DHCP server, am I likely to run into issues? (The old DCs would still be available but I'd hope not responding to DHCP/ DNS requests.)

Or, should I really look to tweak the switch settings in the current location to include the new DHCP server before I move?

I recently Dcpromo'd a domain controller but I'm still seeing this on one of my new 2016 DC's.  The old DC doesn't exist and I don't see any reference to it but for some reason, the new DC is still trying to replicate to it?  I've googled some articles but can't seem to get an answer.  When I run repadmin, I don't see it show up but it's obviously still somewhere in AD.  AD replication is fine and I'm not seeing any errors except this one...

DFSR Error:

The DFS Replication service failed to communicate with partner SERVERNAME for replication group Domain System Volume. This error can occur if the host is unreachable, or if the DFS Replication service is not running on the server.
Partner DNS Address: SERVERNAME.domain.net
Optional data if available:
Partner WINS Address: SERVERNAME
Partner IP Address:
The service will retry the connection periodically.
Running the following cmdlet

Get-DnsServerResourceRecord -ZoneName $zonename -RRtype PTR -ComputerName $dc


Get-DnsServerResourceRecord : Invalid class
At line:4 char:12
+ $records = Get-DnsServerResourceRecord -ZoneName $zonename -RRtype PT ...
+            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : MetadataError: (PS_DnsServerResourceRecord:root/Microsoft/...rResourceRecord) [Get-DnsServerResourceRecord], CimException
    + FullyQualifiedErrorId : HRESULT 0x80041010,Get-DnsServerResourceRecord

Not sure why

Any help much appreciated
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My redhat (guest OS) having issue for not able to resolve the hostname like google.com but able to ping

I didn't do anything at all just to ensure that it can ping Google first and my network subnet like when my redhat added a NAT Network adapter without issue.

After that I connect my fortinet vpn client thr IPSec and still can ping and resolve my private cloud thr hostname.

Next day I do the same thing like connect to my iPad 4G network to my Hp laptop wifi.

Can ping and resolved on my hp laptop even being connected to vpn.

The guest os redhat from virtualbox on nat can ping but not able to resolve now.

Why yesterday can and today can't without changing anything?

We are frequently receiving Netlogon 5774 error on our windows 2012 r2. Due to this we are loosing Internet connectivity and also speed is drastically come down from 20mbps to 5mbps.
We donot have any AD server. Its a plain static IP server with leased line and configured via Juniper Firewall.
Dynamic registration or deletion of one or more DNS records associated with DNS domain 'ABCSERVER.COM.' failed.  These records are used by other computers to locate this server as a domain controller (if the specified domain is an Active Directory domain) or as an LDAP server (if the specified domain is an application partition).  

Possible causes of failure include:  
- TCP/IP properties of the network connections of this computer contain wrong IP address(es) of the preferred and alternate DNS servers
- Specified preferred and alternate DNS servers are not running
- DNS server(s) primary for the records to be registered is not running
- Preferred or alternate DNS servers are configured with wrong root hints
- Parent DNS zone contains incorrect delegation to the child zone authoritative for the DNS records that failed registration  

Fix possible misconfiguration(s) specified above and initiate registration or deletion of the DNS records by running 'nltest.exe /dsregdns' from the command prompt on the domain controller or by restarting Net Logon service on the domain controller.
Hi Expert,

I have some question on command nslookup, can I check in what kind of scenario will you use nslookup? I know it's used to check DNS but do know what kind of situation would use it.

I did nslookup and get default server: unknown, Address:, can I check how come my default server is unknown and the IP address is same as my default gateway?

Also when I nslookup on www.google.com I am getting : www.google.com can't find nslookup: No response from server

Appreciate if any expert can advise me on, sorry if the question is too noob.

I am not able to start my VM on the host ESX i 3.5
I am able to browse the host though web browser and able to log in locally but not able to connect through the Vsphere to get admin control
Need to start a VM which is our DNS and Domain Controller.

i tired to run the VM in command prompt locally by using the command line and get this message
dynamicType= <unset>,
msg = "operation is not allowed.

Please help !!!
Hello Exports. I am trying to build a PS script to resolve DNS names for a few domains. I have the following script:

$domain1 = "test.com"
$notfound = "`tDNS Entry Not Found"
ForEach ($domain in $domain1)      {
      $lyncdiscoverresult = Resolve-DnsName lyncdiscover.$domain1 -Server -ErrorAction SilentlyContinue
if ($lyncdiscoverresult) {
    Write-Host "`tlyncdiscover.$domain1 $(@(foreach ($result in $lyncdiscoverresult.namehost){ '-> '+$result }))" -ForegroundColor Yellow
} else {
    Write-Host $notfound -ForegroundColor Red
select-object Name | Export-Csv "C:\Users\mohsan.chaudhary\Desktop\domain5.csv"

I get the desired output in powershell just fine, but the exported csv file is empty. How can i populate the csv file with the results. Also, I would like to import a csv file with a list of domains, that i am placing into the first variable like this: $domain1 = import-csv "c\location\domain.csv". The PS output displays 'DNS Entry Not found' for all domains, even when i know some of the domains should be resolvable (when i run separately each domain like above, then it resolves fine, but when i import a csv file that includes the domain, then all domains are unresolvable). How can run the above script against a import-csv and export the results to a csv file?
I get the following error when trying to access a server by Remote Desktop Connection from DomainE with an account from DomainH: "The specified domain does not exist or could not be contacted"
I want to specify that there is an outgoing trust relationship between DomainE and DomainH, so that every user from DomainH to have access to resources in DomainE.
The user has admin rights on the server from DomainE and this is happening for all the users in DomanH and all the servers in DomainE.
I don't get this error if I try to connect with a user from the same domain.
The trust is in place in both domains and DNS works properly in DomainE. Also I am able to resolve any host name from one domain to the other.
The DNS servers from the other domain are set as conditional forwarders on each of the mentioned domains and I've checked the DNS servers that are set to the NICs of the servers from DomainE.
The domain functional level is Windows Server 2008R2 and all the servers are using the same version of Windows. The users from the DomainH use Windows 10 to establish the RDP connection to the other domain.
I get no errors when I try to add users from DomainH to security groups in DomainE.

So could you please give me a solution to this problem?
HI 2 Organizations to merge into 1 o365 tenant.
I would like to use 1 Ad connect server (ours) to synch the 2 domains into the 1 tenant to allow the 2 disparate domains (both complete separate dns namespace)

Now both orgs are in separate tenants . AND both have hybrid exchange online.
Now Ive been told that as we "both" have hybrid exchange online - that we will be unable to merge into the 1 tenant.

I would like to know if this is true and why please
Our Active Directory domain says is contoso.com, and our cooperate URL is the same https://contoso.com. URL is publically hosted on AWS and has elastic FQDN, In order to make the URL accesible on internal Newtwork, IT team has created A CNAME record against Public FQDN, But DNS services don't let us create a CNAME with Blank Fields stating "A new record cannot be created. An alias (CNAME) record cannot be added to this DNS name. The DNS name contains records that are incompatible with the CNAME record".  

For now we have created a CNAME with www, with this we open the URL as www.contoso.com, but we want to open it without www internally.
Hi Experts,

we are using KMS since one year.
But now we have a problem with one location. In this location the KMS is activating my clients, servers and clients.
Do you have any ideas ?
I have checked on site on the DNS, the _VLMS record is listed.
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Got 2012R2 server as  DNS
in event logs,for every 4 hours i am getting this "netlogon warning" - which says dynamic registration or deregistration of one or more DNS records failed with the following error.
No dns servers configured for local system.

why this warning keeps arrpearing for every4 hours, is it critical problem or can be ignored? , any help would be great.
i have also attached the error pic.

few more details
dns- its the same server ip
forwarders. - got google and few open dns servers
Hi there,

I must have opened a hole in my firewall so I can get DNS replication to work between my LAN and DMZ. I'm not an expert in Cisco ASA, but I know enough to make me dangerous.
My firewall is a Cisco ASA 5520 with v.8.2 software.

On my LAN subnet ( I have two DNS master servers that should be able to replicate zone data to two DNS slave servers on my DMZ subnet ( The traffic must take place via a dedicated port.

The two DNS servers on the LAN subnet are located on IP and On the DMZ subnet are the addresses and

Here's the setup I'm going to use:

object-group network DNS_SLAVES
  network-object host
  network-object host
object-group network DNS_MASTERS
  network-object host
  network-object host
object-group service DNS_SERVICES tcp-udp
  port-object eq 12345
access group DNS_TO_INSIDE in interface dmz

Open in new window

But before I implement it, I would like some fresh eyes to look at it.

Which port number can I choose, so I certainly do not collide with anything else?
we have several sites under idpcreative.com and i can display all of them except a couple.

The DNS name does not exist.


this is the error message i get on some of them.  other computers can connect to them.
I have a new Windows Server 2016 setup as a new AD server.  I joined it to an existing Active Directory running on Windows Server 2008 R2 then took over the FSMO roles and made it the primary DNS server for the network.

Some thing strange is going on though and I'm not able to figure out why.  I am able to access the \sysvol and \netlogon folders when I use the hostname but not able to when I use the IP address.  

\\newadserverhostname\sysvol <- works
\\newadserverhostname\netlogon <- works
\\(ip address of new AD server)\sysvol <- gets a Windows Credentials challenge
\\(ip address of new AD server)\netlogon <- gets a Windows Credentials challenge

When using the IP address to access the network share, I get a Windows Credentials challenge asking me to enter a username and password.   No matter what username and password I use, the connection fails.  This is happening for both the old AD server and the new AD server.

I checked the Folder Share Properties and Folder Security properties of the SYSVOL folder.  Even if the user is explicitly permitted, I still cannot get it to connect.

Any ideas?
I am trying to add an exchange profile to Microsoft Office 2016 (windows 10). It picks up the email address, however, when it is authenticating it asks for the credentials, but does not accept them and pops straight back up.

So far i have tried; both repairs for office, autodiscover reg keys, checking autodiscover on dns host, Adding a Disable WAM keys, uninstalling office, removing from domain, windows updates.

I have managed to add the profile to Windows 10 Mail and it works.
I have one DC  with DHCP and DNS all in one. I am trying to connect a phone but it does not get an IP from the DHCP, Rebooted the server still getting (The DHCP service failed to see a directory server for authorization) error.

The phone (Cisco IP phone SPA 504G)  just sits on utilization network.
All other devices get IP and the lease time is set to 1 day.  It is when I try and add a new phone.






The Domain Name System (DNS) is a hierarchical, globally distributed system responsible for associating the name of a computer, service or other resource into an IP address for connecting to the Internet or a private network. Most prominently, it translates domain names to the numerical IP addresses needed for the purpose of computer services and devices worldwide.