# Unable to ping using host name, but when I ping using I.P. Address can ping



## romdi29 (Jan 21, 2013)

Hi,

We have, 3 Server. The Role of one server (SRV1) are PDC, RID, Infrastructure, DNS Server and Global Catalog. Other one server (SRV2) are DNS Server, and DHCP Server. It is replication method between SRV1 and SRV2 like a backup server if SRV1 down SRV2 can use as AD and DNS Server. This two server was in Replication Topology Setup. We have also another Server that is a Member Server (SRV3), role of this server are Sql Server, and Exchange Server 2010. This past few days I have a difficult problem about our server, I was unable to ping the workstation using host name if I am login on SRV3 and likewise also to workstation.
sample: ping pc1
 Pinging PC1.srv.com [208.91.197.19] with 32 bytes of data:
 Request timed out.
This PC1, if I run ping using I.P. Address 10.0.0.20 it will show like this
 Pinging 10.0.0.20 with 32 bytes of data:
 Reply from 10.0.0.20: bytes=32 time<1ms TTL=128
It was working. I was unable to understand why can ping using I.P. Address and using host name was unable. And where this I.P Address (208.91.197.19) come up . When I run using NSLOOKUP was working fine the output is like this:
 >pc1
 Server: srv1.srv.com
 Address: 10.0.0.11
 Name: pc1.srv.com
 Address: 10.0.0.20
What I do to temporarily to fix this problem is to run ipconfig /flushdns, ipconfig /registerdns and nbtstat -R, then will work and able to ping the host name and come up the right Private I.P. Address (10.0.0.20). After maybe 10-15 minutes then the problem come up again. I check DNS Server setting (SRV1 and SRV2) I didn't see any unusual problem both side, and I checked also DHCP Server then same no problem I was encounter. If I am facing this problem all pc was unable to access the SQL Server (SRV3) and got also issue on Exchange Server like always prompt user name and password in there email and not connected to Exchange Server.
By the way we have also Appliance Firewall (Cyberoam). The role of this are router, gateway, firewall, port forwarding. I.P. Address of this 10.0.0.250
Now, what I did so that will not come up the Public I.P. Address 208.91.197.19 I configure the firewall to block this I.P. still when I ping other workstation this Public I.P. appear on screen. Is this a virus matter about my issue? What am I to do to fix this problem? I contacted the Cyberoam technical support, IT guy there told me that is not cyberoam issue that is DNS side issue and told me to check the DNS Server side by side. Please help me about this matter. I was have a little bit of knowledge on DNS Server.

Sincerely,
Gerome​


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## srhoades (May 15, 2003)

Try restarting the DNS services on both servers.


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## romdi29 (Jan 21, 2013)

Hi,

I was done already by restarting the DNS Server or even DNS console. And the final what i did is to reboot both server still same issue....

Sincerely,
Gerome


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## srhoades (May 15, 2003)

is there anything being reported in the Windows DNS logs?


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## credible58 (Apr 21, 2012)

Do you have any host or lmhost entries that may be giving the wrong IP?

Try using ipconfig /displaydns to see what is in the DNS cache. ipconfig /flushdns will clear the cache.


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