[Users] Dns resolution failure..

[Kirill Korotaev]

Hello Aaron,

> We've gone down that route with no results.
> 
> What's bugging me (and I can't wrap my brain around it) is that we can 
> ping the outside world, wget to IP addresses, and ssh into external 
> hosts.
from VPS, correct?

 > The only thing that seems to be failing is DNS at the
> application level.. Again, nslookup and host both work without issue.
does dig <some domain> works correctly?
does ping <some domain> works?

do tcpdump (both in VPS and host) and check why UDP packets from 
applications DNS request fail.

Also check that you have no any firewalls in host/VPS.

I feel that there is something simple, but can't say what is wrong 
yet...  :)

Thanks,
Kirill

> -=Aaron
> 
> Kirill Korotaev wrote:
> 
>> You need to check with tcpdump in the host whether your packets go ok 
>> from VE to host system.
>> Does networking work correctly from VE when IP addresses are used?
>>
>> Kirill
>>
>>> Hey all,
>>>
>>> We're seeing a problem where within one particular VE on a host we 
>>> can nslookup or "host" a hostname and everything works.
>>>
>>> But when we try running yum update or wget (even to www.google.com)  
>>> we get "Temporary failure in  name resolution."
>>>
>>> We've dug around on the lists and tried solutions posted there with 
>>> no luck (w.r.t setting forwarding on the main system, etc).
>>>
>>> We're also seeing the following in the logs (not sure if it's a 
>>> red-herring or not):
>>>
>>> Jun 12 15:48:19 FOO sysctl: net.ipv4.ip_forward = 0
>>> Jun 12 15:48:19 FOO sysctl: error: unknown error 1 setting key 
>>> 'net.ipv4.conf.default.rp_filter'
>>> Jun 12 15:48:19 FOO sysctl: error: unknown error 1 setting key 
>>> 'net.ipv4.conf.default.accept_source_route'
>>> Jun 12 15:48:19 FOO sysctl: error: unknown error 1 setting key 
>>> 'kernel.sysrq'
>>> Jun 12 15:48:19 FOO sysctl: error: unknown error 1 setting key 
>>> 'kernel.core_uses_pid'
>>>
>>>
>>> I should mention that all other VE's running on the host work without 
>>> a problem.
>>>
>>> Any ideas?
>>>
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>>
>>
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> 
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