DDNS entries disapearing

[mcaissie]

Hi,

We have a couple of sites running DDNS ( Win2k server + Win2k clients) .
Clients are embeded systems and have a maintenance reboot every night .

In the morning we can see that aroud 20% of the DNS entries have disapeared.
All the missing entries in the DNS get their DHCP lease within a window of
30 seconds .

I think that once the server opens the database to process an update it
cannot buffer
the next request and for some reason it delete the entry without renewing
it.

For now the workaround is to run an ipconfig/registerdns at a random
intervall
following the reboot , but i would prefer to get rid of this and make it
working
as it should.

Anyone have a hint to resolve this ?

Thanks

 

[Ace Fekay [MVP]]

In mcaissie <[email protected]> made a post then I commented below
:: Hi,
::
:: We have a couple of sites running DDNS ( Win2k server + Win2k
:: clients) . Clients are embeded systems and have a maintenance
:: reboot every night .
::
:: In the morning we can see that aroud 20% of the DNS entries have
:: disapeared. All the missing entries in the DNS get their DHCP lease
:: within a window of 30 seconds .
::
:: I think that once the server opens the database to process an
:: update it cannot buffer
:: the next request and for some reason it delete the entry without
:: renewing it.
::
:: For now the workaround is to run an ipconfig/registerdns at a
:: random intervall
:: following the reboot , but i would prefer to get rid of this and
:: make it working
:: as it should.
::
:: Anyone have a hint to resolve this ?
::
:: Thanks

Are all DNS zones on a DC all DDNS?
Is this one domain?
Do the clients just have your internal DNS in IP properties, or is there
also an external DNS?

--
Regards,
Ace

G O E A G L E S !!!
Please direct all replies ONLY to the Microsoft public newsgroups
so all can benefit.

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

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft Windows MVP - Windows Server - Directory Services

Security Is Like An Onion, It Has Layers
HAM AND EGGS: A day's work for a chicken;
A lifetime commitment for a pig.

 

[mcaissie]

"Ace Fekay [MVP]"

In mcaissie <[email protected]> made a post then I commented below
:: Hi,
::
:: We have a couple of sites running DDNS ( Win2k server + Win2k
:: clients) . Clients are embeded systems and have a maintenance
:: reboot every night .
::
:: In the morning we can see that aroud 20% of the DNS entries have
:: disapeared. All the missing entries in the DNS get their DHCP lease
:: within a window of 30 seconds .
::
:: I think that once the server opens the database to process an
:: update it cannot buffer
:: the next request and for some reason it delete the entry without
:: renewing it.
::
:: For now the workaround is to run an ipconfig/registerdns at a
:: random intervall
:: following the reboot , but i would prefer to get rid of this and
:: make it working
:: as it should.
::
:: Anyone have a hint to resolve this ?
::
:: Thanks


Are all DNS zones on a DC all DDNS?

Hi Ace,

Not a DC , a standalone server . We are in a workgroup environment , no AD.
The server runs DHCP and DDNS , there is only one zone , and clients
registers
in that zone .

On the client , the " Use this connection's DNS suffix in DNS registration"
is checked.
The domain name is given by DHCP . The config works , it's only when
there is a lot
of requests in a short period of time that we lost DNS entries.

Is this one domain?

yes , exactly it's a sub-domain ( site.domain.com ) . The DNS authoritative
for the zone
"domain.com" have a delegation for "site" on this DNS server

Do the clients just have your internal DNS in IP properties, or is there
also an external DNS?

The DNS mentionned above is also in the IP configuration of the clients.


The environment is

NOC:
A dns server DNS1 authoritative for domain.com with a delegation for
site.domain.com on
dns2

SITE:
A dns server DNS2 authoritative for site.domain.com and accepting dynamic
updates
A DHCP server updating dns for site.domain.com
Clients getting their address and domain name from DHCP -
client.site.domain.com
Clients have DNS2 and DNS1 configured in IP configuration

 

[Ace Fekay [MVP]]

In

"Ace Fekay [MVP]"


Hi Ace,

Not a DC , a standalone server . We are in a workgroup environment ,
no AD. The server runs DHCP and DDNS , there is only one zone , and
clients registers
in that zone .

On the client , the " Use this connection's DNS suffix in DNS
registration" is checked.
The domain name is given by DHCP . The config works , it's only
when there is a lot
of requests in a short period of time that we lost DNS entries.


yes , exactly it's a sub-domain ( site.domain.com ) . The DNS
authoritative for the zone
"domain.com" have a delegation for "site" on this DNS server



The DNS mentionned above is also in the IP configuration of the
clients.

The environment is

NOC:
A dns server DNS1 authoritative for domain.com with a delegation
for site.domain.com on
dns2

SITE:
A dns server DNS2 authoritative for site.domain.com and accepting
dynamic updates
A DHCP server updating dns for site.domain.com
Clients getting their address and domain name from DHCP -
client.site.domain.com
Clients have DNS2 and DNS1 configured in IP configuration

Thanks for the update. I think if your clients are pointing to the parent
server and registration is trying to go into the child (delegated) server,
that may cause a lag. Is that how you have it set up?

Ace

 

[mcaissie]

"Ace Fekay [MVP]"

In




Thanks for the update.

Thanks to you

I think if your clients are pointing to the parent server and registration
is trying to go into the child (delegated) server, that may cause a lag.
Is that how you have it set up?

ok , here is something new to me .

On the DHCP server the first DNS is DNS2 - this is the authoritative for
site.domain.com,
and the second DNS is DNS1 - authoritative for domain.com.
( by the way DNS1 and DNS2 are located in different location and linked
through a permanent VPN)

The clients receive the same config through scope options 006 DNS Server =
DNS2,DNS1
(they also receive scope options 015 DNS Domain Name = site.domain.com)

My goal is for the DHCP to register names on DNS2 .
Are you saying that the DHCP may try to register on DNS1 if DNS2 is busy
?
If so, is it possible to avoid this ?
I would like to keep 2 DNS in the configuration to allow internet name
resolution for the clients in case
one server goes down.

And even if there was a lag , it would not explain why the entries disapear.

thanks

 

[Ace Fekay [MVP]]

In

ok , here is something new to me .

On the DHCP server the first DNS is DNS2 - this is the authoritative for
site.domain.com,
and the second DNS is DNS1 - authoritative for domain.com.
( by the way DNS1 and DNS2 are located in different location and
linked through a permanent VPN)

The clients receive the same config through scope options 006 DNS
Server = DNS2,DNS1
(they also receive scope options 015 DNS Domain Name =
site.domain.com)
My goal is for the DHCP to register names on DNS2 .
Are you saying that the DHCP may try to register on DNS1 if DNS2 is
busy ?
If so, is it possible to avoid this ?
I would like to keep 2 DNS in the configuration to allow internet name
resolution for the clients in case
one server goes down.

And even if there was a lag , it would not explain why the entries
disapear.
thanks

The registration process works by the machine looking for the zone name that
matches it's Primary DNS Suffix, not the search specific suffic or the
machine specific suffix. Since you do not have an AD environment, then you
will not be using AD Integrated zones. Therefore, one of the machines is
hosting the Primary zone, and the other(s) are hosting a secondary of this
zone. A secondary grabs a read-only copy of the Primary. If a client is
pointing at the secondary zone as the first entry, and a registration
request is sent to it, it will recognize it is a secondary zone, resulting
in the client grabbing the MNAME record, which is the IP address of the
machine hosting the Primary zone, and the reg entry will be sent to that
guy.

So, it depends on what DNS1 and DNS2 are in your scenario. I believe you can
figure out why it's registering into one machine than the other, no matter
which is the first or second in the NIC properties.

As for records disappearing, I would look at which server it is sending the
reg request to (the one first in the list). I would also look at the TTL of
the records.

Ace