• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 275
  • Last Modified:

How does DNS pick what IP to return to the client?

In Active Directory if you have more than 1 domain controller they show up in DNS as (same as parent folder).  So when trying to ping the domain (not the Domain controller) it returns one of the IP's listed in (same as parent folder).  How does DNS chose which IP to return to the client that is requesting it?

Thanks
0
litog
Asked:
litog
  • 2
2 Solutions
 
PlaceboC6Commented:
The SRV record has a priority value on it.

http://support.microsoft.com/kb/232025
0
 
ahmedalnoohCommented:
srv record that belongs to the domain controllers have priority and also somthing called weight also so if same priorty for both the weight value will make one of them win and if also the same so the round robin method will win and the load balancing will make the dns server each query give one of them on the top of the list
0
 
PlaceboC6Commented:
However,  if you modify the priority on the srv record without disabling the function that auto-registers the SRV records...it'll just create another record with the default weight and you'll have multiple records:

Otherwise it is just round robin based off which site the client and DC's are in.  If you have 3 DC's in your default site...and a client in that site/subnet queries..it'll be handed the ip of one of those 3 DC's at random.

To disable auto-registration see the following KB (The netlogon section)

http://support.microsoft.com/kb/246804
0

Featured Post

SMB Security Just Got a Layer Stronger

WatchGuard acquires Percipient Networks to extend protection to the DNS layer, further increasing the value of Total Security Suite.  Learn more about what this means for you and how you can improve your security with WatchGuard today!

  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now