Unsolved
This post is more than 5 years old
326 Posts
0
1499
Backup NLB Servers - name server may be misconfigured
Hello all
windows 2008r2, Networker 7.6.3.7
NLB servers are as below
ping APPV01
Pinging APPV01.abc.com [x.x.x.42] with 32 bytes of data:
Reply from x.x.x.42: bytes=32 time=1ms TTL=128
ping -a x.x.x.43
Pinging APPV01 [x.x.x.43] with 32 bytes of data:
Reply from x.x.x.43: bytes=32 time=9ms TTL=128
ping APPV02
Pinging APPV02.abc.com [x.x.x.44] with 32 bytes of data:
Reply from x.x.x.44: bytes=32 time=1ms TTL=128
ping -a x.x.x.45
Pinging APPV02 [x.x.x.45] with 32 bytes of data:
Reply from x.x.x.45: bytes=32 time=17ms TTL=128
The servers were rebooted and now throwing these error in backup. Was working fine before
39077:save: error, Warning, cannot resolve host 'APPV02.abc.com' to 'x.x.x.42', name server may be misconfigured.
39077:save: error, Warning, cannot resolve host 'APPV01.abc.com' to 'x.x.x.44', name server may be misconfigured.
Backup (Global 1of 2)
appv01
appv01.abc.com
x.x.x.43 (tried with 42 too but same)
appv02
appv02.abc.com
x.x.x.45 (tried with 44 too but same)
Any best practice in backing up NLB servers would be appreciated..thank you
ble1
14.3K Posts
0
September 18th, 2013 01:00
Set in in DNS/hosts table.
Thierry101
326 Posts
0
September 18th, 2013 18:00
Thanks for the reply Hrvoje
But it was working fine before...what could possibly broke it?
thanks again
ble1
14.3K Posts
0
September 19th, 2013 07:00
Well, something happened for sure. In the past I have seen similar issue with multihomed machines (where they had several interfaces within same subnet) and reboot after patching would bring similar situation (it was not patches, but rather order of nics which changed within Windows). It doesn't matter if this is a match to your case or not - point is that something has changed and best way to address it is to address error itself. Your issue seems to indicate that gethostbyip() and gehostbyname() have issues - perhaps DNS is not in place or it started to forward request to second DNS which has different answer - who knows. To get the bottom you need to test is.
Thierry101
326 Posts
0
September 19th, 2013 14:00
Hi Hrvoje
What to test and expected output is the query :-)
Have checked the NLB, Teaming, DNS orders, etc, nslookup
We have another twin APPV servers which wasnt rebooted but working ok so far...have cross check the configs as well..nothing amiss
not finding anything that breaking it....
ble1
14.3K Posts
0
September 19th, 2013 15:00
> What to test and expected output is the query :-)
The error you reported is:
39077:save: error, Warning, cannot resolve host 'APPV02.abc.com' to 'x.x.x.42', name server may be misconfigured.
39077:save: error, Warning, cannot resolve host 'APPV01.abc.com' to 'x.x.x.44', name server may be misconfigured.
Now, you already have hint above - it is reported by save so it is the client that at the time of run could not resolve these servers to IPs given. And the error says that during gethostbyip() return for APPV02.abc.com was not x.x.x.42 (nor was x.x.x.44 for APPV01.abc.com).
Thierry101
326 Posts
0
September 22nd, 2013 15:00
yep
I have no idea how NLB works and its a pain...
C:\Windows\system32>nslookup xx.xx.xx.42
Server: dc-01.xx.xx.xx.xx
Address: xx.xx.xx.10
Name: appv01.xx.xx.xx.xx
Address: x.x.x.42
C:\Windows\system32>nslookup x.x.x.43
Server: dc-01.xx.xx.xx.xx
Address: x.x.x.10
*** dc-01.xx.xx.xx.xx can't find 10.32.64.43: Non-existent domain
C:\Windows\system32>ping -a xx.xx.xx.43
Pinging APPV01 [xx.xx.xx.43] with 32 bytes of data:
Reply from xx.xx.xx.43: bytes=32 time=17ms TTL=128
C:\Windows\system32>
Thierry101
326 Posts
0
September 22nd, 2013 15:00
Hi Hrovje
These were checked:-
-nslookup
-ping
-ping -a
-NLB
-Teaming
-DNS
all returns FQDN and x.x.x.42 which looks ok and non-suspicious but Networker still doesnt like it
Globals 1 of 2 have these entries, setup by vendor (to ensure NLB works-it has been working before)
appv01 (resolves to x.x.x.42)
appv01.abc.com (resolves to x.x.x.42)
x.x.x.43 [resolves to APPV01 but not registered in DNS]-NLB virtual name]
I am trying to understand causes on Networker refusing to backup now since there was no changes at all on backup configs.
ble1
14.3K Posts
0
September 22nd, 2013 15:00
Because what you have may be spoofing. You said yourself, appv01 is 43. Now you say that .43 claims the same. Each IP should have different name associated with.
ble1
14.3K Posts
0
September 22nd, 2013 16:00
It is possible that it uses NB name - check what will ipconfig /all give you.