Solved

How is it possible to ping a computer name and get reply if not in DNS

Posted on 2014-07-25
4
270 Views
Last Modified: 2014-09-16
I have been assigned an existing project that consists of two domains (Domain A and Domain B) on the same physical network. These two domains do not hat trust relationships and each domain has their own domain controllers and DNS servers, but share a common DHCP server and default gateway.

Domain A was the first domain and Domain B was added later to facilitate a company division that is preparing to separate into a new, independent company.

Some computers on Domain A needed to be accessed by computers on Domain B so the prior admin added a DNS zone to the DNS server in Domain B that listed computer host names and IP addresses from Domain A.

There are no WINS servers running or being referenced on the Domain B domain controller

From the domain controller in Domain B, I can ping the computers listed in that DNS zone by computer name and get a reply, as expected.

However, I can also ping computers in Domain A that are not specifically listed in that DNS zone in Domain B, which makes me think that there must be a link I am missing.

The DNS server in Domain B does not have any forwarders and is just using Root Hints.

I have examined the domain controller in Domain B and it does not have any entries in the local hosts or LMHosts files in the c:\windows\system32\drivers\etc folder

How is it possible that I can ping a non-public computer by name that is not specifically listed in a DNS zone, Host file, LMHosts file or via a forwarder to a Domain A DNS?

Thanks,

Dave
0
Comment
Question by:dcadler
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 77

Expert Comment

by:Rob Williams
ID: 40219358
NetBIOS and DNS use multiple methods to resolve names such as those you mentioned LMhost, Hosts, DNS, WINS but also simple name caching.  I forget the order, and it varies based on node type,  but when one fails it tries another.  However you cannot count on caching for reliability.
0
 
LVL 95

Expert Comment

by:John Hurst
ID: 40219368
Given your conditions, you are better off to access a computer in the other domain. I do that reliably whenever I cannot resolve a name by DNS.
0
 
LVL 77

Accepted Solution

by:
Rob Williams earned 500 total points
ID: 40219374
PS-  The following is a good article for a type H (Hybrid) node, the most common, name search order:
http://networkadminkb.com/KB/a118/understanding-dns-client-service-how-name-resolution-works.aspx
0
 
LVL 26

Expert Comment

by:DrDave242
ID: 40220081
It could be a simple NetBIOS broadcast that's resolving that name, since they're all on the same network. Are you pinging just the hostname or the fully qualified domain name?
0

Featured Post

Is Your AD Toolbox Looking More Like a Toybox?

Managing Active Directory can get complicated.  Often, the native tools for managing AD are just not up to the task.  The largest Active Directory installations in the world have relied on one tool to manage their day-to-day administration tasks: Hyena. Start your trial today.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

You might have come across a situation when you have Exchange 2013 server in two different sites (Production and DR). After adding the Database copy in ECP console it displays Database copy status unknown for the DR exchange server. Issue is strange…
OfficeMate Freezes on login or does not load after login credentials are input.
In this Micro Tutorial viewers will learn how to use Windows Server Backup to create full image of their system. Tutorial shows how to install Windows Server Backup Feature on Windows 2012R2 and how to configure scheduled Bare Metal Recovery backup.…
Michael from AdRem Software explains how to view the most utilized and worst performing nodes in your network, by accessing the Top Charts view in NetCrunch network monitor (https://www.adremsoft.com/). Top Charts is a view in which you can set seve…

689 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question