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-   -   Can ping MyDNS1.FQDN and IPs but no other hostnames? (https://www.linuxquestions.org/questions/linux-networking-3/can-ping-mydns1-fqdn-and-ips-but-no-other-hostnames-91276/)

leecason 09-10-2003 11:32 AM

Can ping MyDNS1.FQDN and IPs but no other hostnames?
 
I can ping MyDNS1.MyDomainName.TLD and IP addresses, but no other hostnames?

OS: Red Hat 9, running in VMware Workstation 4 VM, on WinXPP
IP Address: DHCP

Name resolution is not working on this RH9 VM. All pings for a hostname return "unknown host" but ping by IP address works fine. I can ping the first DNS server by FQDN and that works, but not the second DNS server, even by FQDN.

This machine is on a 10,000 node Win2K Active Directory network with Win2K DNS servers. I've installed default RH 8 and RH 9 in VMs and on physical machines on this network before and had everything automagically work via DHCP.

Suggestions ?

td_miles 10-06-2003 01:19 AM

You didn't say if you could ping the second DNS by name ?

If you can ping things by IP address, then you have to assume that IP networking is working fine and the problem is name resolution.

What are the contents of your /etc/resolv.conf file ?

What about if you try:

"dig www.yahoo.com" and right down near the bottom, it will tell you what the server is that it queried, eg:

;; Query time: 250 msec
;; SERVER: 192.168.144.16#53(192.168.144.16)
;; WHEN: Mon Oct 6 16:17:46 2003
;; MSG SIZE rcvd: 508


Now try:

dig www.yahoo.com @139.130.4.4

(139.130.4.4 is a publicly available DNS server, if it doesn't work, then insert your ISP's DNS server IP instead).

chort 10-06-2003 01:28 AM

You need to dig @yournameserver www.google.com and see if that works. The FQDN for the DNS server should be irrelevant because it should be specified by IP in your /etc/resolv.conf.

It sounds like you may not be able to resolve anything outside the DNS zone that your name servers are authoritative for, in which case they're not allowing you to do recursive lookups.

If the name servers that are provided won't allow recursive lookups, either convince the admin to add you to the list of hosts allowed for recursion, find another internal DNS server, setup named on your VM, or use your service provider's DNS (although the last option is not encouraged, since most bandwidth providers don't have nearly enough horsepower on their name servers for all their customers to use them).

leecason 10-06-2003 03:01 PM

DNS problem is resolved
 
Like so many root causes, this one was my error. The DNS servers have been the same on this network for YEARS, so at some point I must have fat fingered in the same info that always worked before. Well, there are new DNS servers now, and since I'm usually working on Windows boxes that get everything via DHCP I never noticed the change. I finally compared the /etc/resolv.conf on a Linux box I had built that was working and noticed the DNS servers were different.

I'm still not sure how /etc/resolv.conf got configured correctly on the physical box and incorrectly on the virtual box, but I'm not blocked anymore.

Thanks all!

Lee


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