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Reverse DNS not working ? 4

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Ejaz

Technical User
Jun 13, 2001
14
GB
Hi, Been looking through various related issues within this forum but still cant see what im doing wrong. I have W2k server, using it to do DNS and DHCP. DHCP is fine. However reverse DNS doesnt work. I created the reverse zone first, then added the forward. After a while names appear in both, hosts and pointers, etc, all looks fine. I can ping addresses and I can ping names, but I dont get the resolution of the name when pinging the address. Where am I going wrong. My clients are mainly 2kpro, some 09, nt, xp, however they all give the same results. Any ideas anyone ???? Thanks for any help.
 
not sure what you mean when you say you don't get resolution of names when you ping...are you saying that if you do a ping -a , that you don't get a hostname? Open an nslookup session, set type to PTR, and see if you can resolve any IP's. Remember the syntax is REVERSE_IP.in-addr.arpa
 
Hi, thanks for that. Still a bit confused. Doing the nslookup with PTR specified works, and produces the reverse host name result required. However, simply pinging with an -a doesnt.If I ping the host name it gives me the IP, but pinging the IP just gives me the IP. Im expecting to see the hostname when I ping the address with a -a arent I ?
 
Yes, a "ping -a IP_ADDRESS" should get you a host name along with the standard ICMP response. That is kind of odd though, unless there's some IP stack corruption. I would say that if your reverse DNS lookup is working, this should not be a problem. I will look into this...
 
Thanks, Im certianly far form an expert in this area, but I figured I was doing thiings correctly, but as you see its not producing the results, and this is an issue for me as I have Samba connectivity which needs hostnames for sharing. Thanks again, let me know what you find........
 
OK. It seems that the ping application will use whatever naming resolution available to it. So, we need to talk about other methods of resolution...do you have WINS running at all? Do you enable NetBIOS over TCP/IP?
 
Hi, yes I enable Netbios over IP and I actually installed WINS a few days ago as I also thought that would fix it. It doesnt seem to have! I guess then the question is have I setup WINS correctly, but then again is it that hard ??
 
Hehe, no it's not that hard, I'm sure you did it right. What happens if you do a ping -a on localhost or 127.0.0.1 ? Do you get resolution?
 
Seeing how we are talking DNS here...Lets assume DNS is doing most of your resolution. I would first verify the the clients are using a valid Windows 2000 DNS server (that you configured for reverse lookup.). I can't tell you how many times, people forget to verify that the client is using the proper DNS servers(I see ISP DNS servers, old Unix DNS servers, etc still being used...This will through off all of your testing.). So, first start your testing by doing this on the CLIENT,

1) IPCONFIG /all (Winipcfg for 9x). Verify that the local client is pointing to the appropriate DNS server.

2) on the client (preferably Win2K or XP), use NSLOOKUP to test resolution. From a CMD prompt, type NSLOOKUP

You should see something like this:

C:\>nslookup
Default Server: MyDNSServerName.CompanyXYZ.com
Address: 10.1.1.41

(The information listed above is the primary DNS server for this client machine. Along with it is the IP address of the DNS server.)

Type a name of a server to test normal DNS resolution. For example, I will type server1.companyxyz.com. This is the result:

Server: MyDNSServerName.CompanyXYZ.com
Address: 10.1.1.41

Name: Server1.Companyxyz.com
Address: 10.1.1.12

(The first entry simply displays the DNS server that was queuried. And the second entry shows that server1 has resolved to IP address 10.1.1.12)

Next Check reverse lookups by typing the IP address of a server in the NSLOOKUP utility. For example, I will type 10.1.1.30. This is the result.

> 10.1.1.30
Server: MyDNSServerName.CompanyXYZ.com
Address: 10.1.1.41

Name: SERVER11.CompanyXYZ.com
Address: 10.1.1.30

(This shows that IP address 10.1.1.30 resolved to Server11.)

3) ON your DNS server, I would check the DNS reverse zones to verify that PTR records exist.

4) It is also a good idea to use the PING -a to verify reverse lookups...I prefer NSLOOKUP because this looks specifically to DNS.

i.e.
J:\>ping -a 10.1.1.30

Pinging Server11.Company.com [10.1.1.30] with 32 bytes of data:

Reply from 10.1.1.30: bytes=32 time<10ms TTL=127
Reply from 10.1.1.30: bytes=32 time<10ms TTL=127
Reply from 10.1.1.30: bytes=32 time<10ms TTL=127
Reply from 10.1.1.30: bytes=32 time<10ms TTL=127


Joseph L. Poandl
MCSE 2000

If your company is in need of experts to examine technical problems/solutions, please check out
 
Hi Guys, thanks for all your help. It would appear that I was doing something a bit stupid......... Followed through Jpoandl's comments above, and all seemed ok. Only when I pinged with the -a did I get the desired affect ie name resolution !!! Now, I know that brontosauras told me to try that ages ago, but unfortunately I had been using ping x.x.x.x -a instead of ping -a x.x.x.x !!!!!! So now it works as im using ping correctly. Adios..........
 
Ejaz,

I'm glad you figured it out... Joseph L. Poandl
MCSE 2000

If your company is in need of experts to examine technical problems/solutions, please check out
 
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