DHCP Not Updating DNS 2008 Server

[guest]

I have a 2008 DC with AD integrated dynamic updates (secure only) set on DNS and DHCP scope set to Enable DNS dynamic updates according to, Always dynamically update DNS A and PTR records. And Discard A and PTR records when lease is deleted. However, it seems our laptops have 2 IPs. One for LAN and one for Wireless. Only the Wireless IP is registering in DNS on the DC and not the LAN IP. I can see in DHCP a pen icon by each fqdn wireless but no pen next to the LAN IP. How can I get both IPs into DNS? And why is DHCP not adding all its IPs into DNS? Thanks...

The pen icon means "Active lease, DNS dynamic update pending. This
address is not available for lease by the DHCP server."

DHCP Tech Reference:
http://technet.microsoft.com/en-us/libr ... 81580.aspx

Also, it may mean that if it is stuck on the pencil icon, it means it
cannot update the record in DNS because it already exists and DHCP
server does not own the record, the client machine does, and therefore
the DHCP server cannot update the record. One way to get around that
is to force DHCP to own the record, but there are few steps you need
to perform to enable this feature, as well as set scavenging options.
Please read my blog in the following link explaining this and a
how-to.

DHCP, Dynamic DNS Updates, Scavenging, static entries & timestamps,
and the DnsProxyUpdate Group (How to remove duplicate DNS host
records)
http://msmvps.com/blogs/acefekay/archiv ... group.aspx


I hope you find it helpful.

Ace

[guest]

>I'm not sure this information specifically addresses the issue where only one IP for each machine is getting registered in DNS when each machine (being laptops) have two (one for wireless, one for LAN). I'd like to see 2 cnames in DNS, but it looks like only the wireless IPs are getting registered. Also, I'm not seeing Option 81 in DHCP. Not sure that's why there's a problem or not. Thoughts?

Hi MarcGel,

Option 081 is actually the DNS tab in DHCP properties (right-click
DHCP server name, choose properties, click on the DNS tab). All those
selections and options are essentially Option 081.

As for why the wireless and not the wired, more than likely because
the wireless is the active interface, assuming they are not plugged in
and connected wirelessly. If they had at any one time registered, such
as when originally setting up the laptop, and you have scavenging
selected, or ven the selection to Discard the lease is up, therefore,
if was scavenged or the wired connection lease was up, then you wopld
no longer see the wireless IP registration in DNS, unless when
originally configured they never were plugged in?

Also, you wouldn't see a CNAME registered, rather you would see a
Hostname (an "A" record) in DNS.

Besides, it *seems* what you are looking for, is duplicate records? So
you would have a laptop with two entries, one for the wireless and one
for the wired interface? Is that what you want it to do? Many IT folks
usually opt to not have this, since it causes issues with connectivity
trying to manage the laptop, especially if using management tools,
such as SMS.

Ace

[guest]

As I understand that your issue is the DHCP record can’t be registered in DNS server.
If I misunderstand please let me know

Is there any reservation setting for wireless NIC on you DHCP server ?
Is this happen only one particular computer or all computer which has multi NIC? And Is the issue laptop a member computer of domain ?
Have you attempt to use “ipconfig /release” and “ipconfig /renew” on your laptop for re-register the DNS record ?

The DHCP server require the client's Option 81 to update the pointer (PTR) and Host (A) resource records of DNS server.
Please understand that Option 81 is not listed in the Scope Options nor the Server Options in DHCP. As Fekay said the option 81 is the setting of DNS tab in DHCP properties.
You can also check the option 81 setting value with show optionvalue switch of netsh command
Please reference this article

The values that appear for DHCP option 81 and the corresponding GUI meanings that are shown in the DHCP MMC snap-in in Windows Server 2003
http://support.microsoft.com/kb/945397

Using DNS servers with DHCP

http://technet.microsoft.com/en-us/libr ... 7034(WS.10).aspx

Please refer to this post where we discussed the same issue:

Clients can't register in DNS server.

http://social.technet.microsoft.com/For ... f7762ad12c

DNS server is not updating

http://social.technet.microsoft.com/For ... 1e58a3e8b5

Thanks

Tiger LI

[guest]

I do have a backup DC with DNS on it. It also has aging set to 1 day. Just changed that to 90. Again, not sure about best practice. Went ahead with manually deleting my wireless IP from DNS, turned off wireless card, ran ipconfig /registerdns. Waiting to see. As for duplicate host records, that's what I want. I want 2 A records for each Host, one IP for wireless and one for LAN NIC. DHCP seems to have less pens waiting to write to DNS.

Ok, everything updated fine and now my A record is correct in DNS (LAN NIC IP registered).

[guest]

doing the manual delete of the wireless IP from DNS and then from the Host PC doing ipconfig /registerdns worked. It looks like these settings helped.

To isolate the issue I suggest please check if worked with following step

1、 scavenging the DHCP server manually first ,and delete the wireless DNS and DHCP record on both server.

2、 disable the client’s wireless NIC and connect to network via wire NIC only.

3、 execute ipconfig /release, /renew, and /registerdns on your client side.



If it not worked ,Please check the steps blow and retry the steps above again



1、 set the AD integration DNS zone dynamic update to “nonsecure and secure”

2、 check the option “register this connection's addresses in DNS” of your client pc’s wire NIC.


I'm still not getting both IPs in DNS though. Is there something I could check to allow 2 (A) records for each laptop (1 for wired and 1 for wireless IP)? That would be ideal. It looks like a lot of those DHCP waiting to write Pen icons have gone away. I'll keep reading your articles to see if there's something I missed. Thanks!

[guest]

Good to hear it's now working.

As for scavenging, I usually leave it to the default 7 days. It works
nicely. You will want to keep it around the same time as your DHCP
lease length.

Also, having two IPs for the same hostname is usually not what we want
to see in an environment, at least not for a workstation, and is
certaintly not a best practice. After all, think of it this way - if
you try to manage the workstation, and the management tool (whether
Computer Management, SMS, SCCM, third party, etc) tries to resolve the
client, DNS sees there are two IPs, therefore it will Round Robin
between the two, and the management tool, or even if trying to UNC to
the machine, may get the wrong IP and not be able to connect.

Ace