[plug] mozilla problem

[James Devenish]

In message <1048264018.1296.946.camel at jlmpc>
on Sat, Mar 22, 2003 at 12:26:58AM +0800, Jon Miller wrote:
> Ever since I've had this problem with bind v9.  I've noticed that 
> mozilla (especially) the one on the home desktop (rh7.3) does not work
> all the time.

*#*#*#*#*#*#*#*#*/You really need to determine whether it's anything to
do with Mozilla or whether it is a generic problem/*#*#*#*#*#*#*#*#*#*
There's no point posting bug reports to mozilla.org if in fact uplink is
losing UDP packets, for example. Conversely, if you find that your DNS
resolution if working fine then there may be a bug in Mozilla.

> It only works on certain sites (google.com, but not google.com.au)> If
> I try to do a search only 1 out of 5 searches will work.

You have made an omission here: you have not described the nature of the
failure. Searching with Google is a fairly "high-level" activity in the
sense that a whole orchestra of lower-level things need to work
invisibly in the background. Because of this, there are a large number
of distinct failures that can occur and "does not work" is probably not
a sufficient description. By analogy, a surgeon does not know he needs
to re-attach a severed arm if all the GP knows is that there's a rumour
about the patient having trouble picking up large dogs.

Although some operating systems and typical applications (and by this I
mean Microsoft Windows and Windows-style software) give your error
messages that consistent entirely of "An error occurred. Something
didn't work. Please click here to sign up with MSN.", most other
operating systems and their software will give you more information.
(And if that is still not enough, there are way of narrowing the
problem down.)

I don't know if Mozilla is giving you any useful message at all, but if
it is (or if you are using a web proxy and it is giving you messages),
those may be important. For instance, "no servers responded" would be
usefully distinct from "domain does not exist". On the other hand, "name
could not be found" may be indicative of either of the previous two
example messages.

> Since this is a desktop system accessing the Internet via the
> VPN.  I'm not sure what the problem is.  The VPN is as such.  The home
> server (rh7.3) is connected to the office server and all request are
> made via the office gateway server.

Roughly in this order:
1/ Check your local resolver settings.
2/ Check that the host sites (e.g. Google) are working.
3/ Check whether your computer can contact its upstream name servers.
4/ Check whether the upstream name servers are working.
5/ Check whether proxies are causing a problem.
6/ Check whether applications on your computer can resolve names
   via the regular name resolution libraries.
7/ Check whether applications are working.

For #1, do `cat /etc/resolv.conf` (if that's the right thing for
RedHat). It will indicate what name servers your computer is using. You
may also need to have a look at /etc/nsswitch.conf to see that hosts may
come out of DNS. Presumably, both of these files are fine (since things
worked for you in the past). However, you now have an insight as to what
your upstream server is. Presumably this is the one that is running BIND
9?????????????????????????????????? Or not??????????????????????????????
If you resolv.conf indicates that 127.0.0.1 is your server, then look at
your bind settings as see what 'forwarders' you are using. If these
values are nonsense, you will need to fix them. Note: you should have at
least one "local" name server. (E.g. the Guild uses UWA's name servers
as its first port of call.) If you are relying only on the root name
servers, then you are at the mercy of the wind and the rain and it is.
And it is not polite. But, depending on how BIND was installed, this
might happen by default.

Now, #2 is true. Google is working.

#3 and #4: if you have BIND 9 installed then you should have the 'dig'
programme available to you. If so, run `dig @my.upstream.server
www.google.com.au` to make it contact a name server directly. You should
get a correct response within a second (sometimes less than a blink of
the eye). You can also do `dig www.google.com.au +trace` to make sure
that the Google is alive and that its DNS is not broken. However, you
might not be able to do this from within your "VPN".

#5 and #6: run a fairly transparent command-line programme like 'wget'
(e.g. `wget -S -O /dev/null www.google.com.au` to see whether
applications can rely on your operating system to resolve names. If you
*have* to use a web proxy within your VPN, then you would have to set up
wget to use that proxy. A quicker way would be to use telnet to make
manual connections, but you need to know the syntax.

#7: you may wish see if your Mozilla "profile" is part of the problem.
For example, you could clear the "history" and clear the "cache" and
proceed from there. You could also create a new profile (or move your
.mozilla directory so that Mozilla can't find it and creates a new
profile from scratch).