Re: DNS Problem
- From: ibuprofin@xxxxxxxxxxxxxxxxxxxxxx (Moe Trin)
- Date: Mon, 25 Feb 2008 19:02:23 -0600
On Mon, 25 Feb 2008, in the Usenet newsgroup comp.os.linux.networking, in
article <13s5kbhiuv5v68@xxxxxxxxxxxxxxxxxx>, Joseph Hesse wrote:
Its my impression that the DNS servers listed in /etc/resolv.conf are
the ones always used for name lookup.
With the exception of DNS query tools like 'dnsquery', 'dig', 'host'
and 'nslookup' which _can_ be told to use other name servers as an
option, that's basically correct.
The resolv.conf file generated when I installed F8 is:
-------------------------------------
; generated by /sbin/dhclient-script
Actually, it's not the file generated by the install program, but the
file generated by your DHCP client every time you boot.
search domain.actdsltmp
nameserver 192.168.0.1
nameserver 208.42.42.42
-------------------------------------
I am not sure why 192.168.0.1 is there since it is my gateway address.
Because that's the addresses specified by your DHCP server, and you
have configured your DHCP client to overwrite the existing file.
I manually edited resolv.conf to reflect the DNS servers given to me
by my ISP. The edited one is:
-------------------------------------
; generated by /sbin/dhclient-script
search domain.actdsltmp
man 5 resolver and see if that line is appropriate. Usually, it's not.
When I restart my computer, the resolv.conf file goes back to the "just
installed" version.
No, it's going to the values handed out by your DHCP server.
My ActionTec DSL modem was manually configured to know about the two
DNS servers given by my ISP but this has no affect.
Not enough details. Is the DSL modem operating a name server? Use one
of those four tools above to query the modem asking about an internal
as well as external hostname. Does the modem supply the answer or not?
Occasionally I get problems which appear to be DNS related but I am not
sure. In any case, I think I should have both DNS servers available.
The resolver believes the first answer it receives. If you ask the DNS
about internal hosts - such as 'poobah', the resolver will attempt to
figure out a "full" name, and ask the name server[s] about that (such
as 'poobah.example.com'). Because you have the 'search' directive, it
will then try 'poobah.domain.actdsltmp' and
'poobah.example.com.domain.actdsltmp' - neither of which are likely to
resolve. The name server will return a NXDOMAIN error, and that's the
end of the querys. It does not matter if the "other" name server knows
the correct answer - because the first name server that answered said
the name isn't valid.
Any name server you list should be able to answer ALL questions. If
you have a local domain setup, the normal technique is to point your
systems at a/the name server[s] that can answer queries about that
domain, and have the name server (not your clients) forward unknown
queries to an outside name server, or have it recursively resolve
the name by performing a normal name search on it's own. This is
detailed in the DNS-HOWTO.
1. I have my network (/etc/sysconfig/network-scripts/ifcfg-eth0)
configured to use DHCP rather than a static IP.
If your computer isn't moving from network to network, DHCP may be a
larger problem than it's worth.
3. As soon as I installed F8 I pointed my /etc/yum.repos.d files to
point to my local yum server. I did this since I have several F8
machines and it is easier to use a local yum server. This is probably
not relevant.
Correct to both statements.
4. I have another F8 computer which uses a static IP and I don't have
this problem with resolv.conf.
Yes, it's not running the DHCP client which has been set to overwrite
the various system files.
Old guy
.
- References:
- DNS Problem
- From: Joseph Hesse
- DNS Problem
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