powershell help!

Question

powershell help!

John JY 221

Hi all,

we need to convert all servers DNS dynamic records to static records within all Windows 2012 domain controllers AD.
Can anyone help on how to convert through powershell script?

Thank you!

Rich Matheisen 48,116 Reputation points

2022-03-25T02:23:34.95+00:00

Can you explain how the records are created in DNS?

I'm guessing that you're trying to avoid having the records for server scavenged by the DNS server, and that the servers are not using DHCP to acquire their IP addresses.

Do your client machines use DHCP?

Is DHCP responsible for updating the DNS or are the clients configured to update their A and PTR records?

I'm guessing again that you have both servers (non-DHCP machines) and clients (DHCP users) in the same DNS zone (and either the DNS server, or zones, are set to do scavenging of expired records)
John JY 221 Reputation points

2022-03-26T16:46:40.333+00:00

@Rich Matheisen Your guessing is right. All servers are assigned static IP address and all clients (DHCP users) use DHCP.

you have both servers (non-DHCP machines) and clients (DHCP users) in the same DNS zone (and either the DNS server, or zones, are set to do scavenging of expired records)

yes. same zone (one zone like mydomain.local).

What is the better way to do this? any way to output which records are converted successfully or unsuccessfully?

Thank you for your continuing support.
Rich Matheisen 48,116 Reputation points

2022-03-27T21:34:39.17+00:00

Are your servers (which do not use DHCP) configured with "Register this connections addresses in DNS"? If they are then thy should be refreshing that registration periodically (which changes the timestamp on the A record). As long as they refresh the information in DNS, and your scavenging values for the zone aren't set to periods shorter than the interval at which the servers refresh the data, you shouldn't have a problem because the record will never become stale and subject to removal by the scavenging activity of the DNS server.

I don't know of any way to uncheck the box that says to remove the record when it becomes stale, though. At least I haven't been able to find any.

What you might want to try is to configure the server's NIC to NOT register the addresses in DNS. Then remove and recreate the A records using PowerShell. Try that with a set of "dummy" A records to see if simply creating a new A record checks that box. If it doesn't, then you'll have to stop depending on the server to create new A records and do that job yourself.

3 answers

Your answer

Rich Matheisen 48,116 Reputation points

2022-03-25T02:23:34.95+00:00

Can you explain how the records are created in DNS?

I'm guessing that you're trying to avoid having the records for server scavenged by the DNS server, and that the servers are not using DHCP to acquire their IP addresses.

Do your client machines use DHCP?

Is DHCP responsible for updating the DNS or are the clients configured to update their A and PTR records?

I'm guessing again that you have both servers (non-DHCP machines) and clients (DHCP users) in the same DNS zone (and either the DNS server, or zones, are set to do scavenging of expired records)
John JY 221 Reputation points

2022-03-26T16:46:40.333+00:00

@Rich Matheisen Your guessing is right. All servers are assigned static IP address and all clients (DHCP users) use DHCP.

you have both servers (non-DHCP machines) and clients (DHCP users) in the same DNS zone (and either the DNS server, or zones, are set to do scavenging of expired records)

yes. same zone (one zone like mydomain.local).

What is the better way to do this? any way to output which records are converted successfully or unsuccessfully?

Thank you for your continuing support.
Rich Matheisen 48,116 Reputation points

2022-03-27T21:34:39.17+00:00

Are your servers (which do not use DHCP) configured with "Register this connections addresses in DNS"? If they are then thy should be refreshing that registration periodically (which changes the timestamp on the A record). As long as they refresh the information in DNS, and your scavenging values for the zone aren't set to periods shorter than the interval at which the servers refresh the data, you shouldn't have a problem because the record will never become stale and subject to removal by the scavenging activity of the DNS server.

I don't know of any way to uncheck the box that says to remove the record when it becomes stale, though. At least I haven't been able to find any.

What you might want to try is to configure the server's NIC to NOT register the addresses in DNS. Then remove and recreate the A records using PowerShell. Try that with a set of "dummy" A records to see if simply creating a new A record checks that box. If it doesn't, then you'll have to stop depending on the server to create new A records and do that job yourself.

Answer 1

Anonymous

Here's an example where you can loop through the addresses.
https://community.spiceworks.com/topic/2198046-how-to-sort-ip-addresses-properly-with-get-dnsserverresourcerecord

John JY 221 Reputation points

2022-03-24T16:09:18.577+00:00

any way to output results? Thank you.

Answer 2

Rich Matheisen 48,116

The Get-DnsServerResourceRecord should return all the "A" records for the host. You just have to iterate over the list, changing them one at a time.

John JY 221 Reputation points

2022-03-23T20:17:14.113+00:00

Hi @Rich Matheisen

Thanks for the info. The Get-DnsServerResourceRecord will return all A records which includes workstations. So, I have a csv file with server name and IP addressees.

How do I get around to convert a dynamic host name with multiple IPs? Or any better way?

Thank you!
Rich Matheisen 48,116 Reputation points

2022-03-24T02:57:22.417+00:00

You were already given a link that demonstrates how to remove the expiry date from a DNS resource record.

Since you have a CSV with the name and IP address(es) you only need to use the -Name parameter on the cmdlet and then check each resource record returned for that name for a matching IP address -- then change that record. If you want to change ALL the resource record for the name regardless of the IP address you only need the name of the machine in your CSV file and then change all the records returned.
John JY 221 Reputation points

2022-03-24T14:59:42.497+00:00

@Rich Matheisen

If a server with multiple IP addresses like mentioned in the example, the script fails
It only works with a server with one dynamic record. How should I convert a server with multiple dynamic records to static?
Thank you for your help!

Here is the script I used and Thanks @Anonymous

foreach ($server in (Get-Content c:\Computers.txt)) {

$OldObj = Get-DnsServerResourceRecord -Name $server -ZoneName "mydomain.local.com" -RRType "A"
$NewObj = $OldObj.Clone()
$NewObj.TimeToLive = [System.TimeSpan]::FromHours(0)
Set-DnsServerResourceRecord -NewInputObject $NewObj -OldInputObject $OldObj -ZoneName "mydomain.local.com" -PassThru

}

Answer 3

Anonymous

Here you go again?
https://learn.microsoft.com/en-us/answers/questions/232821/anyone-can-help-to-turn-dynamic-dns-server-records.html

--please don't forget to upvote and Accept as answer if the reply is helpful--

Anonymous

2022-03-19T20:24:44.463+00:00

Just checking if there's any progress or updates?

--please don't forget to upvote and Accept as answer if the reply is helpful--
John JY 221 Reputation points

2022-03-22T15:28:08.183+00:00

DSPatrick,

Thank you very much for continuing support!:-)

the issue about multiple IPs assigned to one host remains. in the following example, the script ran and server1 with 10.1.1.1 was converted to static.

but, server1 with 10.1.1.2 and 10.1.13 are not converted to static. Is there a way to convert server1 with 10.1.1.2 and 10.1.13 through script?

example:
If a dynamic host name with multiple IPs as the followings,
server1 10.1.1.1
server1 10.1.1.2
server1 10.1.1.3

Thank you for your help!

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