DNS update problems

[mcaissie]

Hi ,

I have a DHCP + DDNS running on a Win2k server . The setup is running
fine , when the client gets its IP from the DHCP the name is registered in
the
DNS .

But every once in a while , the dns update doesn't work , we can see the
address
given by the DHCP with the correct zone name , but nothing in the DNS .
We run an ipconfig /renew on the client and the entry appears.

Have anyone experience the same problem ?

Configuration is ok since it works 95% of the time .

I suspect thasince both DHCP and DNS runs on the same PC , maybe the
DNS update timeout during a cpu peak .

Any Idea on what is causing this ?

thanks

 

[Kevin D. Goodknecht Sr. [MVP]]

In

Hi ,

I have a DHCP + DDNS running on a Win2k server . The
setup is running fine , when the client gets its IP from
the DHCP the name is registered in the
DNS .

But every once in a while , the dns update doesn't work ,
we can see the address
given by the DHCP with the correct zone name , but
nothing in the DNS . We run an ipconfig /renew on the
client and the entry appears.

Have anyone experience the same problem ?

Configuration is ok since it works 95% of the time .

I suspect thasince both DHCP and DNS runs on the same PC
, maybe the
DNS update timeout during a cpu peak .

Any Idea on what is causing this ?

I've seen this where the DHCP lease time is more than the DNS scavenging
time. This causes DNS to scavenge the record before the lease is renewed. If
you setup DHCP with the default settings, the lease expires in 8 days, if
you enabled scavenging on the zone with the default settings the zone is
scavenged in 7 days. This means the zone is scavenged one day before the IP
lease would have to be renewed.

 

[mcaissie]

In

I've seen this where the DHCP lease time is more than the DNS scavenging
time. This causes DNS to scavenge the record before the lease is renewed.
If
you setup DHCP with the default settings, the lease expires in 8 days, if
you enabled scavenging on the zone with the default settings the zone is
scavenged in 7 days. This means the zone is scavenged one day before the
IP
lease would have to be renewed.

Kevin,

Thanks for your answer.

I have not enabled scavenging on the dns zone but the DHCP lease is quit
long (14 days).
I'll try to enable Scavenging and configure it to more than 14 days and
check the behavior.

regards

 

[Kevin D. Goodknecht Sr. [MVP]]

In

I have not enabled scavenging on the dns zone but the
DHCP lease is quit long (14 days).
I'll try to enable Scavenging and configure it to more
than 14 days and check the behavior.

14 days is quite long, why not reduce the lease time?

 

[mcaissie]

In

14 days is quite long, why not reduce the lease time?

We are planning to do that also .

We have several remotely managed sites with no IT on site , and the
goal was that if the server goes down we have a week to replace it before
the clients lost their IP. But we never needed so much time.