Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.




534 posts

Ultimate Geek
+1 received by user: 24

Subscriber

Topic # 87331 26-Jul-2011 09:45 Send private message

Howdy,

So my problem is that the application I support is suddenly taking 12s to return a hostname for a given IP.  Prior to D day, it was taking a more acceptable 1-5s.  I've got the task of convincing IT its their network thats changed as opposed to our application.

I imagine its a fairly typical Win2003 domain (don't have sys admin rights so can't nose about) with Windows running the DNS and DHCP.
Using nslookup tells me that there are no Reverse Lookup zones configured (i.e 2s timeout when querying by IP)
On the server NICs there's no defined WINS server, LMHosts lookup is not enabled and NetBIOS is set to "Default-Use NetBIOS settings from the DHCP server". 
There are no Host file entries on any of the servers.
Server dns and arp caches have been flushed.

The connecting clients have a mixture of both static and dynamic IPs

My questions is, how does reverse lookup even happen in this type of environment anyway?

Create new topic
7709 posts

Uber Geek
+1 received by user: 290

Trusted
Subscriber

  Reply # 497926 26-Jul-2011 11:02 Send private message

Does nbstat -c or nbstat -r (start > run > cmd > nbstat ?) give you any useful info?



534 posts

Ultimate Geek
+1 received by user: 24

Subscriber

  Reply # 498023 26-Jul-2011 13:54 Send private message

Ragnor: Does nbstat -c or nbstat -r (start > run > cmd > nbstat ?) give you any useful info?


Brilliant, thanks for that.

Running nbtstat -c regularly is showing the netbios cache is being updated, which seems to be the only source of reverse lookups.
-r is shows that the vast majority of resolutions are being done by Broadcast which'll explain the increased times in the app logs.

So I wonder what could change on a network to go from an average of 3s resolution to over 12s?? 

Create new topic




Twitter »
Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:




News »

Trending now »
Hot discussions in our forums right now:

Moment of Truth?
Created by BarTender, last reply by joker97 on 24-Sep-2014 06:53 (421 replies)
Pages... 27 28 29


Festival of Democracy
Created by gzt, last reply by ubergeeknz on 23-Sep-2014 16:11 (138 replies)
Pages... 8 9 10


Geekzone giveaway: ADATA SSD SP610 256GB and ADATA PV110 Power Bank
Created by freitasm, last reply by Lias on 23-Sep-2014 22:26 (48 replies)
Pages... 2 3 4


Gigatown Beaten - Im So Jelly of Taranaki
Created by raytaylor, last reply by FiShYmAn on 23-Sep-2014 20:34 (24 replies)
Pages... 2


How do we get more people out to vote?
Created by nate, last reply by Geektastic on 23-Sep-2014 22:02 (45 replies)
Pages... 2 3


GCSB Surveillance Vans?
Created by snowball, last reply by dickytim on 24-Sep-2014 06:12 (56 replies)
Pages... 2 3 4


Vodafone Wellington Cable Issues
Created by notna, last reply by TimA on 23-Sep-2014 22:19 (17 replies)
Pages... 2


Looking for online productivity software recommendations
Created by fpsware, last reply by networkn on 23-Sep-2014 16:49 (16 replies)
Pages... 2



Geekzone Live »
Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.

Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.