DNS resolution problem.

Hi Guyz.

First of all you should know that I am new to DNS management.

The problem is:
I installed Acitve Directory with the DNS on the same server. and have only one server as AD Domain Controller.

I also installed linux on another machine, where I hosted virtual Websites, under the same ip and different names.

I created Host A records against each name of the website pointing to the Linux machine IP address.

now the problem is that Some times the browser opens the page with the name without any errror, and suddenly sometimes it stops without any error and do not directs to the linux server to open the pages.

then again after some times it automatically starts resolving to the page.

I am using Widnows Server 2008 R2 and Red Hat Enterprise Linux 5, both on ESXi5 Free license.

Can any one help me solve the issue ?

Any question can be asked to clarify the issue.

Are you seeing DNS problems when it isn't working? Is it an internal site ot external to the internet as well? If it's windows, use nslookup on the command line and see if it is a name resolution problem (use dig for linux/mac). If it's a DNS resolution issue, it's probably something with the config.

it in only internal site. using windows server 2008

i added only forwarders for the purpose to allow the clients to go to internet through the internal DNS.

i m using windows, and in nslookup, the names resolve. but it do not ping on the name during the time when the it is not resolving on the browser.


Below error is always in the Best Practices Analyzer.


also two other warnings are there in this section, one mentioning that i only have prefered DNS address, second mentioning that scavenging service is disabled.

I have only one dns and one active directory domain.

I have installed the DNS automatically with the AD installation, and only added forwarders as mentioned above. so i do not see where i did any miss-configuration? Guidance is appreciated

If you can resolve the name via nslookup when you are having an issue, it probably is not a DNS problem. DNS won't affect your ability to ping something as long as the hostname resolves. All DNS is there to do is name resolution. So it sounds like that is working. You have a different issue if you can ping it when it works (I'm assuming) but can't when it doesn't. Maybe networking related or something on your server actually hosting the sites.

If you have secondary dns specified in your client workstation along with your windows server, perhaps for whatever reason your query is going directly to the secondary dns server that doesn't have your local lan IP hostnames.

Doug has a good idea. Can you post an ipconfig /all and let us know if you can ping the IP of the website and/or fqdn?

hi.

I can ping the IP but on the name it is not pinging.

It is happening every time. some times, it is pinging from one pc and not from others

in ipconfig /all, ip address, gateway, DNS address of local server and ISP dns addresses are taken from DHCP. also today i configured WINS and assigning WINS IPs from the DHCP too

In server 2008 load the DNS snap-in. Right click on the server name in the DNS snap-in and select properties. Under the interfaces tab verify the server is listening for DNS queries on the proper interface(s). Post, verbatim, and warnings or erros in your DNS logs under event viewer as well.

When you say computers can't ping by name, but can by IP, is this for computers in the LAN or outside the LAN; or both?

all this is in LAN environment only. and i am checking with FQDN and Netbois names both.

Ok, what's the results of the rest of the stuff you need to check?

on interfaces tab as you mentioned, the checkbox 'All IP Addresses' is checked.

There are no warnings or error in the eventviewer in DNS logs.

and at the time of the error, it also resolves in nslookup.


I think like CaptPikel mentioned, it is not related to DNS.

I also think to assign only one DNS IP and Check. using the recommendations of Doug G

It sounds like DNS is setup and functional. If you can resolve the website using both a forward and reverse lookup, then I agree it's not a DNS issue. However, the odd thing is you can ping the website by IP 100% of the time, which I would think would eliminate an underlying network related issue.

You also mentioned that when the problem occurs, some computers can still ping the website by name, while other's can't; is that correct? If so, when pinging the site by name, it should show the IP the site is resolving to when the ping command is issued. Are the PCs that can ping vs the PCs that can't all listing the same IP for the site?

You can check your dns with tools like nslookup and if there is a windows version available, dig.

all pcs are listing the same ip for the sites. on the target server only one ip is there.


how to check the resolution for reverse lookup zone.

i just check it with nslookup. by entring the FQDN of the site.

e.g. Site1.Domain.local, and it gives the ip of the target server.

Sounds like DNS is working properly.