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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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what are the things to check before IP change on windows server?
How to find what all application has IP hard coded? any tools to find what all application are dependent on old IP?
Change of reverse lookup ip on pointer record and host A record and static IP on server and anything else need to be change after changing static IP on server
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After my previous post
I tested and moved this to production.  things have gone terribly.  As soon as I stood up the second CAS server, all the clients started trying to talk to it, even though I had not made any of the load balancing DNS entries.  When I shut it off, all the client would not work at all!! (So much for failover cluster>:( )  At this point I am just tying to remove it.  I have uninstalled exchange and removed it from the domain, but all my clients are now not connecting at all.  Some one please help, I am desperate :(
Hi I have a server that has Centos7 that does not have an GUI Interface installed. By accident for some reason it looks as though during the install I did not set the IP Address details of Nic1and these should be static. I am trying to set it so that the IP address details of Nic 1 is subnet mask is, gw is and the dns I was going to just set as (Google DNS Servers)
Can you help on the commands to run to set this please. The server has 2 nics but only nic1 is plugged in.  if I run the command ip a this is what I get (please see attached file). I assume the nic is that called enp2s0f0
Hello Experts,

How does TXT record affect O365 hybrid migration.
I am trying to run the HCW minimal version and getting a msg at the domain ownership part of the wizard. Attached screenshot.

1- We are running HCW to create to send/receive connectors
2- We want mail to flow to our on premise first the get redirected to the cloud once we start migration the mailboxes

How does the TXT configuration work and how does it affect the mail-flow?

So we are having an issue where everyone in company A is receiving a bounce back when emailing anyone in company B. company B migrated to Office365 a while back and they report no other companies are having issues emailing them.
DNS resolution for the companyb.com domain resolves to Office365. The bounce back is received on mobile devices, OWA, laptops internally and externally for companyA. The server generating the bounce back is the old email server
I asked IT for companyB to check their DNS records for any stale records, but they assure companyA that no stale records are seen.

Thoughts on what else to check?

Hi.  We are recovering from Irma and I have noted a strange issue on a few networks where their internet went down.  The specific account I am concerned with is configured as following:
Netgear Router bridged to Comcast Modem - Router
2011 SBS Server - DNS, DHCP & AD - file sharing   IP

I have configured the workstations to use the following configurations:
LAN IP (each PC has it's own)


After setting this up on each PC, I still cannot connect to, nor ping the server or the other devices on the network.
They should be on a domain network, and they are definitely NOT home or Public at the least.

As this has happened on different networks, and the common link is they are Comcast and this has happened since we lost internet (it is popping in and out intermittently).  I just need to get the workstations to talk to the server.

Any ideas or insights?
We have Exchange 2007 and I want to enable Outlook Anywhere feature for the purpose of office 365 staged migration.
We already have a working OWA 2007 for the users and I have completed the following steps a, b and c

a) I had purchased multi domain SSL certificate with ( exchangemail.myorg.co.uk and autodiscover.myorg.co.uk)  and have installed successfully on our exchange server.
b) I have installed Enable RPC over HTTP
c) On the EMC- Sever Configuration-Client access- I have Enabled Outlook Anywhere.

Our DNS and firewall is hosted by  external company . Do I need to ask them to create CNAME record for autodiscover.myorg.co.uk  to point to the same IP of OWA( Exchange Server)
Any help would be great, Thanks in advance
Hi Experts ,

We Run active directory 2008r2 domain and forest. with some 2012r2 into it.
All DNS servers are also AD Controllers.
When we add a DNS record , should that replicate instant or do we need to wait the replication schedule?
Is there a way to sync DNS records instant if ?

Hi Experts,

on my SQL AG I have some new DNS errors.
I use SQL2014 in an availabilty group.
On the Failover cluster I have  this errors, many time each day.
Can you help me out ?

Cluster network name resource 'BMD_BMD-DB' failed registration of one or more associated DNS name(s) for the following reason:
DNS operation refused.
This will be wordy...trying to give all the info that I know to help out the experts.
We have converted from Ex2010 to Ex2016, we have hub in dmz.
we have a new cert from digicert- owa.company.com, mail.company.com, autodiscover.company.com
Cert has been applied. mail is flowing fine, in and out.
When you open outlook you get a cert error- ex2016.company.local - the name on the cert is invalid or does not match the cert.
I know you can't assign a cert to a .local or internal server name anymore. so I'm not sure what to do?
something else that is very odd in our DNS. we have an A record autodiscover.company.local x.x.x.11 (.11 is ex2010), If I change it to .15 (.15 ex2016 new server) email will not get to exchange- we get a bounceback message stating that the email is rejected due to content filtering. even if the email is nicely worded and formatted properly.
So 2 strange issues.
Last very strange issue...If I manually create an outlook profile- servername: ex2010, username and click check name the servername: ex2010 magically changes to ex2016 and the check name works and there is no cert issue.
I want my 90 users to not have the cert error, and not have to go to 90 workstations and manually recreate every persons profile.
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Hi Experts, AFAIK there are 3 ways to anti-spam to an Exchange 2016 environment: SPF, DKIM and DMARC

I can configured SPF record on domain control panel but not sure about the 2 others, does anyone have experience with them? Can we configure them on Exchange mailbox server, or public DNS of ISP?

Many thanks in advance,
Hello, in my company we are planning on starting to decommission our local forest. it is a one domain forest with 8 domain controllers.We are currently in the process of migrating, building local servers to our parent companies domain.
Can anyone recommend any good books that walk you through the steps, mention important points to consider,
help planning on domain/ forest decommissioning...etc, thanks in advance.
Hi All,

Can anyone here please let me know what do I need to do in order to successfully cutting over the Anti Spam solution from onPremise Linux VM into the Cloud Solution with no data loss or user email flow interruptions?

As at the moment on my Exchange 2013, the Send Connector Smarthosts listing the local IP address for the 2x Linux VMs.

Do I just change it to the Public IP address of the Cloud Anti-Spam provider ?

Note: My Public DNS server is running on my On-premise Windows Server 2008 R2 VMs.

i installed bind and setup example.com domain on my centos 6.9.

trying to find what is the causes here.

[root@dns01 ~]# named-checkconf /etc/named.conf
[root@dns01 ~]#

[root@dns01 ~]# named-checkzone example.com /var/named/rev.example.com
zone example.com/IN: loaded serial 2017091501

[root@dns01 ~]# named-checkzone example.com /var/named/fwd.example.com
zone example.com/IN: loaded serial 2017091501

[root@dns01 ~]# host -v -t ns example.com.
Trying "example.com"
;; connection timed out; trying next origin
Trying "example.com"
;; connection timed out; no servers could be reached
We had a firewall that ran all of our dns for our websites and had a pointer to an external site. We had the old firewall replaced and the new firewall isn't capable of running dns. The guy who setup dns records on the domain controller. Putting in the A Records worked for the websites we hosted but not for the one outside of our network.

I created a forward look up zone with the sitename.ca and added an A host record with the external ip, and another with www and external ip.

Any suggestions?
I have another issue where internal users are not receiving delivery delayed notifications.  When running some of the tools on MX toolbox I get two errors SMTP banner mismatch and the other which I am lost at is SMTP connect failure.  When I go under out external DNS settings the STMP server address what pointing to secureserver.com which we don't use I set it to SMTP.mydomain.com would point to mx.mydomain.com but I am getting the failure and the resolution point to our website IP when running the MX tools even know I changed it.  Do I need this SMTP records to point the the MX?
I am trying to decide which option would be better for redirecting a web URL to a new URL. Basically I have a website autohill.com that I would need to redirect to web.customauto.com and the autohill.com website will be shutdown eventually. which should I use for my external hosted DNS and which should I do for my internal DNS? CNAME or create a new A record with the new name and point the existing A record to the new IP address of the new website?
Our Windows 2012 R2 DHCP servers which are setup in a failover relationship are set to update the client DNS information. Our DNS servers are set to allow secure and non-secure dynamic updates. We already have an account in place that will handle the secure updates. When I look in the Security tab of a DNS record I see the "System" account is listed as the owner and not our service account.

I have already read the following article and the setting listed is already in place.
Thanks for checking out my question.  It seems simple, but it requires a little explaining.  
Goal: Be able to configure my home Outlook to send emails from Outlook by authenticating to our Exchange server
Environment: Exchange 2013 / Outlook 2013
DNS Flow (to explain how the traffic flows from internet-to-Exchange-server): mail.company.com translates to public IP address. Public IP address NAT's directly to my CAS server.

When I configure my Outlook client, I am setting up a POP3 account.
Incoming mail server: mail.company.com
Outgoing mail server: mail.company.com
Username: Myemail@email.com
Incoming server (POP3) Port: 995 (using SSL)
Outgoing server (SMTP) Port: *Here is the problem*

When I choose "Test Account Settings" when creating my Outlook profile, it's a 2 step process.  
1st step: Log onto incoming server --> SUCCESSFUL
2nd step: Send test e-amil message --> FAILS

On my firewall, the ports I am forwarding to the Exchange server are: 995, 993, pop3, smtp, https, TLS(587).  However, when working with with my firewall vendor, we let in EVERY port and it still failed.  I'm thinking this is an Exchange issue, but I'm unsure where to start.  
Send/Receive Connectors?

Thanks again!!
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Hi All ,

Need your help to understand why Favicon Icon is not showing up for a single site collection in IE 11 only, I have tried deleting IE cookies , Cache , hard refresh , IIS reset, Flush DNS etc but nothing worked, any suggestions ? below is scenario .
Single web application with with 2 site collections http://SC1 and http://sc1/sites/sc2

In IE :
Favicon show up for http://sc1
Favicno does not show up for http://sc1/sites/sc2

In Chrome :
Favicon shows up for http://sc1
Favicon shows up for http://sc1/sites/sc2

Thanks in advance.
Hello Guys,

Due to bad internet connectivities in my country (Lebanon) and the need to have fail-over plans, I am considering to move my Exchange Box from a public IP (from a specific ISP) to a Dynamic DNS from a "reliable" Dynamic DNS vendor.

Anybody has an experience with how to do so ?

Help is greatly appreciated.

Currently we have dev, test and uat for non-prod environments. And test and uat are going through Akamai and use their Forward Rewrite cloudlet to determine which server to go to.

Now we have a new project. The project team asks separate environments from BAU, so it wouldn't impact the BAU work. They proposed to use dev2, test2 and uat2, but to be able to use Akamai with these new domains we have to do a lot of works, such as create new configs, register new certificates, copy all the rules... and also DNS change, firework change...

I am thinking to still stick to the existing URL, but create a clone site. So for example, under test.XXX.com.au, we have 2 versions of sites: V1 and V2. So is there a way the IIS could determine to pass the request to test.XXX.com.au\V1 or test.XXX.com.au\V2? By default it always goes to V1, but by adding some information, such as something in the header, IIS would know which version to go to. And the URL would always be test.XXX.com.au.

Thank you.
Company is on BIND DNS.  I setup a new AD with new Zone for that AD.  
In Windows DNS have BIND Forwarders IPs with Unable to resolve in Server FQDN.  
Do I need to enable BIND Secondaries?  

What else I need to enable on BIND and Windows DNS to have users connected to successfully resolve new AD?
2nd Domain Controller DNS server missing Zones.  1st has Forward Lookup Zones.  2nd doesn't.  Do I need to add it manually?
To add new DCs into DNS.  Should i add a short name or FQDN?  In order to machines to see DCs by name.  Currently DCs only pingable by IPs.
Company DNS is on BIND DNS.
Thanks in advance.






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.