JK, Might want to get some more coffee there.
:-) PS Thanks for the chuckle. I needed it this morning. On Wed, Aug 25, 2010 at 9:43 AM, Kennedy, Jim <kennedy...@elyriaschools.org>wrote: > “It's strikes me odd that DNS would allow multiple entries for the same IP > address. Is that normal behavior” > > > > Yes, they both registered their DNS with the DNS server…the low use PC did > it a month ago, it was shut off and its lease expired and that address was > given to a new PC. > > > > The fix is to set up savaging to lower levels on your DNS server. > > > > > > http://technet.microsoft.com/en-us/library/cc759204%28WS.10%29.aspx > > > > > > > > *From:* Bob Hartung [mailto:bhart...@wiscoind.com] > *Sent:* Wednesday, August 25, 2010 9:37 AM > *To:* NT System Admin Issues > *Subject:* DHCP and DNS Anomoly > > > > I've got an odd situation with DHCP and DNS creating a confusing situation. > > I use SmartCode VNC Manager for remote support. Every hour it queries all > our network PCs to see if they are active or not. It uses the PC's name to > resolve the IP address. I happened to notice that a very low use PC showed > active when I was pretty confident it wasn't turned on. When I remoted into > it, it turned out to be a different PC. Hmmm... > > I went to the command prompt and tried pinging both the low use PC as well > as the PC I wound up connecting to and they both resolved to the same IP > address. I tried "ipconfig /flushdns" to see if I had an error in the DNS > cache but that made no difference. > > Next stop was the DHCP server. We have a MS Window 2003 SP2 PDC that hosts > both DNS and DHCP. The low use PC had been off long enough that there wasn't > even an entry for it in the IP address leases. There was an entry for the PC > I wound up connecting to. I tried the same ping testing on the PDC as I had > on my PC and got the same results. > > Next stop was the DNS server. Ah ha! There were 2 entries in the Forward > Lookup Zones for that IP address for each of the PCs I was pinging. Oddly, > in the Reverse Lookup Zones, there was only one entry and it was for the low > use PC. > > It's strikes me odd that DNS would allow multiple entries for the same IP > address. Is that normal behavior? Since these pointer records are > automatically created by an interaction between the DHCP and DNS servers, > shouldn't there also be a process that would delete DNS pointers based on > expired DHCP leases, particularly since the IP address had been handed out > to a different PC? > > I know I could resolve this issue by either turning on the low use PC and > getting a new IP address lease or by simply deleting the expired DNS pointer > but I'd like to understand why this can happen and if there's a way to > configure things so it doesn't continue to happen. > > Thanks. > > ---------------------- > > Bob Hartung > Wisco Industries, Inc. > 736 Janesville St. > Oregon, WI 53575 > Tel: (608) 835-3106 x215 > Fax: (608) 835-7399 > e-mail: bhartung(at)wiscoind.com > > > > > > > > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
