users Digest, Vol 131, Issue 86

[Rick Stevens]

On 01/29/2015 06:56 AM, William W. Austin wrote:
> On 2015-01-28 15:45:36, users-request at lists.fedoraproject.org wrote:
>
> ======quoted message from Gordon Messmer <gordon.messmer at gmail.com>, subject "Re: Suddenly can't get nameserver resolution on FC21 after ..."======
>> On 01/28/2015 07:02 AM, William W. Austin wrote:
>>> I have checked my ifcfg-* files under/etc/sysconfig/  (all 3 links
>> of
>>> each of the 2 nics) and they are unchanged. My /etc/hosts file is
>>> unchanged
>>
>> DNS is configured in /etc/resolv.conf.  Look there.
>>
>> Attempt to ping your DNS servers to verify they are reachable.
>>
>> Use "dig" to query them directly:
>>    dig @<dns IP address> <hostname>
>
> Apologies - I neglected to include:
> A) I can ping my gateway (route/cablemodem) just as before
> B) I can ping all 3 of my nameservers with no trouble
> D) Using dig (as you suggest) works correctly and resolves properly/
> C) My /erc/resolv.conf is unchanged (and identical those on 2 other machines which work correctly).
> D) IF I have the ip-address of a website (I can get that using another machine on my network), I can use the address in a browser and actually bring up the site.
>
> Nevertheless I cannot ping, ssh or telnet to, or sftp/ftp to ANY site (even those on my internal network) unless I have the ip address of the machine.
>
> So to me these are a clear indication that for some reason this system is refusing to use the nameservers as such.
>
> The reason WHY this is the case still escapes me, and any help with the matter would be greatly appreciated.

First, NEVER respond to a digest. Write a new message with an
appropriate subject line and submit that to
users at lists.fedoraproject.org.

Second, check your /etc/resolv.conf file and make sure it has DNS
servers listed in it.

Third, if there are nameservers, ensure you can ping them.

Fourth, try something such as:

	host google.com ip-address-of-nameserver

to see if it resolves:

	[root at prophead Network]# host google.com 8.8.8.8
	Using domain server:
	Name: 8.8.8.8
	Address: 8.8.8.8#53
	Aliases:

	google.com has address 216.58.219.46
	google.com has IPv6 address 2607:f8b0:4007:80a::200e
	google.com mail is handled by 30 alt2.aspmx.l.google.com.
	google.com mail is handled by 50 alt4.aspmx.l.google.com.
	google.com mail is handled by 40 alt3.aspmx.l.google.com.
	google.com mail is handled by 20 alt1.aspmx.l.google.com.
	google.com mail is handled by 10 aspmx.l.google.com.

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- Rick Stevens, Systems Engineer, AllDigital    ricks at alldigital.com -
- AIM/Skype: therps2        ICQ: 22643734            Yahoo: origrps2 -
-                                                                    -
-      Do you know how to save five drowning lawyers?  No?  GOOD!    -
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