DNS Client Update

I am trying to learn DHCP and DNS, and have a question.

I see that a DHCP client will update its A record in DNS, and that the DHCP
server will update the PTR record. Further, you can specify in the DHCP
server settings (the middle DNS tab) that the DHCP server do both A and PTR
records.

So, if the DHCP server is doing updates of both records, does the DHCP
client still attempt the A update, or is it aware that the server is taking
care of it?

Hello Buck,

You can configure the DHCP scope settings with option 81 for that step:
http://technet.microsoft.com/en-us/l...34(WS.10).aspx

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups
** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm


> I am trying to learn DHCP and DNS, and have a question.
>
> I see that a DHCP client will update its A record in DNS, and that the
> DHCP server will update the PTR record. Further, you can specify in
> the DHCP server settings (the middle DNS tab) that the DHCP server do
> both A and PTR records.
>
> So, if the DHCP server is doing updates of both records, does the DHCP
> client still attempt the A update, or is it aware that the server is
> taking care of it?
>

Thanks Meinholf. That was very helpful. The documentation in the link says

When this option is issued by a qualified DHCP client, such as a
DHCP-enabled computer running Windows 2000, Windows XP, or a Windows Server
2003 operating system, option 81 is processed and interpreted by a DHCP
server running Windows Server 2003 to determine how the server initiates
updates on behalf of the client. If the server is configured to perform DNS
dynamic updates, it takes one of the following actions:
....


Where do you set this option on a DHCP client, if anywhere?

Thanks very much.




"Meinolf Weber [MVP-DS]" <meiweb@(nospam)gmx.de> wrote in message
news:. com...
> Hello Buck,
>
> You can configure the DHCP scope settings with option 81 for that step:
> http://technet.microsoft.com/en-us/l...34(WS.10).aspx
>
> Best regards
>
> Meinolf Weber
> Disclaimer: This posting is provided "AS IS" with no warranties, and
> confers no rights.
> ** Please do NOT email, only reply to Newsgroups
> ** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm
>
>> I am trying to learn DHCP and DNS, and have a question.
>>
>> I see that a DHCP client will update its A record in DNS, and that the
>> DHCP server will update the PTR record. Further, you can specify in
>> the DHCP server settings (the middle DNS tab) that the DHCP server do
>> both A and PTR records.
>>
>> So, if the DHCP server is doing updates of both records, does the DHCP
>> client still attempt the A update, or is it aware that the server is
>> taking care of it?
>>
>
>

a website always needs an ftp protocol


"Buck Turgidson" <> wrote in message
news:hpd9st$ocp$...
> I am trying to learn DHCP and DNS, and have a question.
>
> I see that a DHCP client will update its A record in DNS, and that the
> DHCP server will update the PTR record. Further, you can specify in the
> DHCP server settings (the middle DNS tab) that the DHCP server do both A
> and PTR records.
>
> So, if the DHCP server is doing updates of both records, does the DHCP
> client still attempt the A update, or is it aware that the server is
> taking care of it?
>

Hello Buck,

In the Windows DHCP server properties you can configure the settings that
enable option 81.

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups
** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm


> Thanks Meinholf. That was very helpful. The documentation in the
> link says
>
> When this option is issued by a qualified DHCP client, such as a
> DHCP-enabled computer running Windows 2000, Windows XP, or a Windows
> Server
> 2003 operating system, option 81 is processed and interpreted by a
> DHCP
> server running Windows Server 2003 to determine how the server
> initiates
> updates on behalf of the client. If the server is configured to
> perform DNS
> dynamic updates, it takes one of the following actions:
> ...
> Where do you set this option on a DHCP client, if anywhere?
>
> Thanks very much.
>
> "Meinolf Weber [MVP-DS]" <meiweb@(nospam)gmx.de> wrote in message
> news:. com...
>
>> Hello Buck,
>>
>> You can configure the DHCP scope settings with option 81 for that
>> step: http://technet.microsoft.com/en-us/l...34(WS.10).aspx
>>
>> Best regards
>>
>> Meinolf Weber
>> Disclaimer: This posting is provided "AS IS" with no warranties, and
>> confers no rights.
>> ** Please do NOT email, only reply to Newsgroups
>> ** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm
>>> I am trying to learn DHCP and DNS, and have a question.
>>>
>>> I see that a DHCP client will update its A record in DNS, and that
>>> the DHCP server will update the PTR record. Further, you can
>>> specify in the DHCP server settings (the middle DNS tab) that the
>>> DHCP server do both A and PTR records.
>>>
>>> So, if the DHCP server is doing updates of both records, does the
>>> DHCP client still attempt the A update, or is it aware that the
>>> server is taking care of it?
>>>

"Buck Turgidson" <> wrote in message news:hpdd7q$igh$...
> Thanks Meinholf. That was very helpful. The documentation in the link says
>
> When this option is issued by a qualified DHCP client, such as a
> DHCP-enabled computer running Windows 2000, Windows XP, or a Windows Server
> 2003 operating system, option 81 is processed and interpreted by a DHCP
> server running Windows Server 2003 to determine how the server initiates
> updates on behalf of the client. If the server is configured to perform DNS
> dynamic updates, it takes one of the following actions:
> ...
>
>
> Where do you set this option on a DHCP client, if anywhere?
>
> Thanks very much.


Meinolf mentioned where Option 081 is configured (DHCP properties, DNS tab), where you set to force updates of any client. Keep in mind, Windows clients are set this way by default, on how the respond during the DORA (Discover, Offer, Request, Acknowledgment). Windows 2000 and newer, as well as non-Windows clients, that support Option 081, will process this option, as well as any other options presented (003 - router, 006 - DNS, etc). In Windows, it's enabled by default. It works in conjunction with the interface's properties, IP properties, Advanced, DNS tab, at the bottom whether to register this connection or not and what additional domain names to register, if any. With non-Windows clients, I believe it's similar.

To actually view the Option 081 options or config in Windows, I don't think is possible, just as looking how it applies Option 006, the DNS entries. It's part of the DHCP client process. At least if there is a way, I am not aware of it other than at the system level, which possibly the MSDN dev group would be a better venue to post this.

I hope that helps.

--
Ace

This posting is provided "AS-IS" with no warranties or guarantees and confers no rights.

Please reply back to the newsgroup or forum for collaboration benefit among responding engineers, and to help others benefit from your resolution.

Ace Fekay, MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services

If you feel this is an urgent issue and require immediate assistance, please contact Microsoft PSS directly. Please check http://support.microsoft.com for regional support phone numbers.

Hi Buck,

A further reference for you:

http://support.microsoft.com/default...en-us;317590#3

scroll down to the section on 'How DHCP/DNS Update Interaction Works' where
it says:

"You can use the DHCP server to register and update the PTR and A resource
records on behalf of its DHCP-enabled clients. When you do so, you must use
an additional DHCP option, the Client FQDN option (option 81). This option
permits the client to provide its FQDN as well as instructions to the DHCP
server on how it would like the server to process DNS dynamic updates (if
any) on its behalf.

When this option is issued by a qualified DHCP client, such as a
DHCP-enabled computer that is running Windows 2000, it is processed and
interpreted by Windows 2000 DHCP servers to determine how the server
initiates updates on behalf of the client.

For example, you can use any of the following configurations to process
client requests:
The DHCP server registers and updates client information with its configured
DNS servers according to the client request.

After you install a new DHCP server, this configuration becomes the default
configuration for Windows 2000 DHCP servers and clients. In this mode, any
Windows 2000 DHCP client can request the way in which the DHCP server
performs updates of its host A and PTR resource records. If possible, the
DHCP server accommodates the client request for handling updates to its name
and IP address information in DNS.

To configure the DHCP server to register client information according to the
client's request, open the DHCP properties for the server, click the DNS
tab, click Properties, and then click Update DNS only if DHCP client
requests.
The DHCP server always registers and updates client information with its
configured DNS servers.

This configuration is a modified configuration that is supported for Windows
2000 DHCP servers and clients. In this mode, the DHCP server always performs
updates of the client's FQDN and leased IP address information, both its
host A and PTR resource records, regardless of whether the client has
requested to perform its own updates.

To configure a DHCP server to register and update client information with
its configured DNS servers, open the DHCP properties for the server, click
the DNS tab, click Properties, and then click Always update DNS.
The DHCP server never registers and updates client information with its
configured DNS servers.

To use this configuration, the DHCP server must be configured to disable
performance of DHCP/DNS proxied updates. When you use this configuration, no
client host A or PTR resource records are updated in DNS for DHCP clients.

To configure the server to never update client information, open the DHCP
properties for the DHCP server or one of its scopes on the Windows 2000 DHCP
server, click the DNS tab, click Properties, and then clear the
Automatically update DHCP client information in DNS check box. By default,
updates are always performed for newly installed Windows 2000 DHCP servers
and any new scopes that you create for them."

Hope that helps a bit.

Anastas
"Buck Turgidson" <> wrote in message
news:hpd9st$ocp$...
>I am trying to learn DHCP and DNS, and have a question.
>
> I see that a DHCP client will update its A record in DNS, and that the
> DHCP server will update the PTR record. Further, you can specify in the
> DHCP server settings (the middle DNS tab) that the DHCP server do both A
> and PTR records.
>
> So, if the DHCP server is doing updates of both records, does the DHCP
> client still attempt the A update, or is it aware that the server is
> taking care of it?
>