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elaw

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Accessibility from one server to another using DNS suddenly gets stopped

Greetings!!!

I have two Windows 2008R2 server Server A access Server B with the name netbios name.  But suddenly it stops access server B wihtout any error.  But you can still ping with the IP address.

I could not find any reason why this does like this.  But if I disable the network card and enable the network card, it starts working and this is a quick fix.

However, I need to find out the cause of this.
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Ganpar
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Your Secure channel might have broken...

You can check it by nltest /Server:[TargetServer Name] /SC_Query
http://support.microsoft.com/kb/158148
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elaw

ASKER

what is the example if we have two servers
Server A
Server B
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ASKER

I have found the example and i have run the command.  the command was successfule because there is no issue at the moment.
I will re run the command when I come accross the same issue.

so as you think that the it could be the problem if the secure channel is broken and this nltest shows as well.  Then what is the resolution to fix the problem.
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ASKER

I just want to understand this problem.  
I still can ping the target server with the IP address.  But I am unable to ping the target server with the netbios name.  But when disable and enable the network card on the source machine then it is able to ping the target the server with the netbios name.
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Krzysztof Pytko
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If you find any issue with SC then please reset it
Use following code

Nltest /Server:[TargetServer Name] /SC_RESET:<DomainName>
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ASKER

well this is a hyper-V virtual machine
As Krzysztof said please verify u r NIC driver and update us.......
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ASKER

Krzysztof I agree with you.  but I need to know what is the issue.  I will appreciate if someone can help me.
One more think, please ensure of the latest integration Hyper-V  features are installed on virtual machine.

Additionally please check event logs on Hyper-V and that "faulty" machine to check if there are no any hints for that

Krzysztof
Are you getting any events related to DNS from where we can find the roor cause. There is something causing your DNS

there is another simplest way to resolve this issue instead of disableing & renabling NIC card... Just restart the servives.

You can type this in cmd in single go...

net stop dns & net stop netlogon & nbtstat -RR & nbtstat -R & ipconfig /flushdns & net start dns & net start netlogon & ipconfig /registerdns  & net stop w32time & net start w32time & w32tm /resync /rediscover & net stop ntfrs & net start ntfrs & repadmin /syncall /AeD &  gpupdate /force
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ASKER

Thanks auti for this commands.

but I need to resolve this issue that it should not happen again
And one more thing, what king of virtual network configuration are you using on a guest machine (external, internal etc.)?

Krzysztof
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ASKER

This is running on Hyper-V and this is internal for the Hyper-V
Hello elaw,

Can you give us some event IDs if there are any in your server related to DNS.
OK, so this is allowing only communication between servers themselves no access out of box. Is there DNS server also running on that Hyper-V server ?

Can you check what will happen if you change NICs from internal to external ? Maybe then the issue will disappear?

Krzysztof
Do the servers have STATIC DNS Entries or are you relying on the server registering itself in DNS?

Disabling and reenabling the NIC Will force it to register its IP With the DNS Server.
Servers should really have stativ DNS A Records added by hand, if you have not.

This MIGHT be your problem.
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ASKER

Yes, Neilsr, you are right there is a Static DNS entry.

What could be the issues please let me know.
Can you try using the fully-qualified name and see if the problem recurs?

When using just the netbios name, the network may be relying on broadcasts to resolve name to the IP address.