asked on

Cannot ping FQDN after changing the server IP

I changed the IP address of a server. I have another server that needs to connect to it for backups. When I ping the server that I changed the IP using the FQDN it finds the previous IP and the ping fails. If I ping the new IP it finds it.

If I ping the same server from another server using the FQDN it finds the correct IP.

I've done ipconfig /flushdns twice.

So from the server that cannot ping the FQDN what is wrong and how do I fix it.

Damian

Check the NICs.

Make sure you have static IPs, and perhaps disable any other NICs that you're not using to make sure the server hasn't decided to 'adopt' another NIC.

Query your DNS server, using NSLOOKUP to test the resolution to the other servers etc.

J.R. Sitman

ASKER

Thank you I'll test it as soon as I can

Ashok Dewan

DNS server takes time.

Check this https://www.inmotionhosting.com/support/domain-names/dns-nameserver-changes/domain-names-dns-changes
https://serverfault.com/questions/579813/updating-dns-after-changing-static-ip

timgreen7077

it could be you need to wait for DNS replication. It generally replicates in about 15 - 60 minutes. if this issue persists then make sure that there are not static entries in DNS for that server. if there are static entries you will need to re-ip that A RECORD with the new IP

Shaun Vermaak

Did you run

ipconfig /registerdns

Open in new window

from this server?

David Sankovsky

For starters, make sure that you have the right DNS server - it hsould be the Domain internal one, not google or other public ones.
If you do, check if the problematic server has a static resolution in the hosts file - might've stayed there from debugs and was forgotten about.

J.R. Sitman

ASKER

It has been about 12 hours since I made the change
Both servers have static IP's and only 1
Both have the correct DNS servers
I verified from the DNS server that the old IP was not there
I ran ipconfig /registerdns and I will check logs later for errors.
I ran NSlookup. However, there are errors see below. 172.16.1.14 is a DC, DNS server. 172.16.1.37 is the new IP of the server that cannot be reached via FQDN from 172.16.1.42. 172.16.1.42 is the server that needs to reach 172.16.1.37 via FQDN.

Microsoft Windows [Version 6.3.9600]
(c) 2013 Microsoft Corporation. All rights reserved.

C:\Users\Administrator.LASPCA>nslookup
Default Server: spcala292.laspca.corp
Address: 172.16.1.14

> ipconfig /registerdns
Unrecognized command: ipconfig /registerdns
> ipconfig ?
Unrecognized command: ipconfig ?
> ipconfig
Server: spcala292.laspca.corp
Address: 172.16.1.14

*** spcala292.laspca.corp can't find ipconfig: Non-existent domain
> ipconfig /all
Unrecognized command: ipconfig /all
> exit

C:\Users\Administrator.LASPCA>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : RPS_VM
Primary Dns Suffix . . . . . . . : laspca.corp
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : laspca.corp

Ethernet adapter Ethernet 2:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Hyper-V Network Adapter
Physical Address. . . . . . . . . : 00-15-5D-01-0B-07
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 172.16.1.37(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . : 172.16.1.6
DNS Servers . . . . . . . . . . . : 172.16.1.14
172.16.1.9
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{FF9434FC-1627-4418-8D68-D81B70A85A70}:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

C:\Users\Administrator.LASPCA>nslookup
Default Server: spcala292.laspca.corp
Address: 172.16.1.14

> server 172.16.1.37
Default Server: RPS_VM.laspca.corp
Address: 172.16.1.37

> server 172.16.1.42
Default Server: [172.16.1.42]
Address: 172.16.1.42

> set q-mx
> laspca.corp
Server: [172.16.1.42]
Address: 172.16.1.42

DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Request to [172.16.1.42] timed-out
> server 172.16.1.37
DNS request timed out.
timeout was 2 seconds.
Default Server: [172.16.1.37]
Address: 172.16.1.37

> set q-mx
> laspca.corp
Server: [172.16.1.37]
Address: 172.16.1.37

*** [172.16.1.37] can't find laspca.corp: No response from server
> laspca.corp

J.R. Sitman

ASKER

I just found that the old server was listed on one of the DNS servers, but not the other. I deleted it. Hopefully, that will fix the problem.

J.R. Sitman

ASKER

just wanted to make sure that it is clear, I can ping the FQDN from all servers except one.

J.R. Sitman

ASKER

here is the latest Nslookup.

Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.

C:\Users\jsitman>ping rps_vm

Pinging rps_vm [172.16.1.96] with 32 bytes of data:
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.

Ping statistics for 172.16.1.96:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

C:\Users\jsitman>ping rps_vm

Pinging rps_vm [172.16.1.96] with 32 bytes of data:
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.

Ping statistics for 172.16.1.96:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

C:\Users\jsitman>nslookup
Default Server: SPCALA292.laspca.corp
Address: 172.16.1.14

> server 172.16.1.37
Default Server: RPS_VM.laspca.corp
Address: 172.16.1.37

> exit

C:\Users\jsitman>ping rps_vm

Pinging rps_vm [172.16.1.96] with 32 bytes of data:
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.
Reply from 172.16.1.42: Destination host unreachable.

Ping statistics for 172.16.1.96:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

C:\Users\jsitman>nslookup
Default Server: SPCALA292.laspca.corp
Address: 172.16.1.14

> server rps_vm
Default Server: rps_vm.laspca.corp
Address: 172.16.1.37

>

Shaun Vermaak

Where are you pinging FQDN in #a42488118? RPS_VM.laspca.corp is FQDN and RPS_VM is the NetBIOS name.
Do you have correct suffixes added?

J.R. Sitman

ASKER

if I ping rps_vm.laspca.corp or rps_vm from Udpserver (172.16.1.42) both pings return "destination host unreachable"

atlas_shuddered

ipconfig /flushdns on the affected server?

Shaun Vermaak

I've done ipconfig /flushdns twice.

In OPs question

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David Sankovsky

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Ashok Dewan

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J.R. Sitman

ASKER

Made the change in the Host file and that fixed it. Before I close this, is there an explanation why this would happen?

David Sankovsky

Host file precedes any DNS lookup
So even if the DNS was correct, if the host file pointed to the wrong address, the computer would go to the wrong one.

<As a side note, I should point out that on Linux machines the DNS resolution order can be changed so that the host file be used only afterthe DNS failed, I assume it can also be done on windows, but I do not know how>

Ashok Dewan

1) system first check itself
2) then it check DNS cache.
3) then it check to host file.
4) at the end it ask to DNS server on network.

J.R. Sitman

ASKER

Editing the Host file fixed the problem. Is that file needed or can it be deleted?

David Sankovsky

Deleting it is useless as the system will recreate it.
Just don't edit it unless you have to.

J.R. Sitman

ASKER

thanks

J.R. Sitman

ASKER

thank you