70846 - Conn: "Failed to connect" when receiving an answer from local DNS server

Status: VERIFIED WORKSFORME

(Core :: Networking, defect)

Description

[tgodouet]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.0 i686; en-US; 0.9) Gecko/20010301
BuildID:    2001030105

When I'm offline and I try to get a page, Mozilla send a DNS request.
If I go online while Mozilla is still trying to resolve the address
of the page, and Mozilla finally gets it, it shows a popup "failed
to connect to server".
(By "offline" and "online", I mean I'm connected to my ISP or not :
it is not about mozilla function "Work offline")


Reproducible: Sometimes
Steps to Reproduce:
Switch off your modem.
Try to reach an internet page.
Wait a moment, then start your connection with your ISP,
reload the conf of your DNS server (I don't know if it is really necessary). 
Mozilla still tries to resolve the address of the page.
The DNS server finally give the ip address for the requested page.

Actual Results:  We get a popup "Fail to connect to server".

Expected Results:  Mozilla should start to load the page and display it.

I use a dial-up system at home, with a server running diald
and a DNS server, which forward its requests to my ISP DNS server.
When I'm connected to my ISP, a script runs a "/usr/sbin/ndc reload".

Comment 1

[tgodouet]

The exact error message written in the popup seems to be :
"Connection timeout".

And another problem related : the popup shown blocks all the other windows
downloading, while it should only block the window it is related to.

Comment 2

[tgodouet]

Sorry about the last comment : i was wrong.
The exact (you can trust me this time :)) ) is :

"The operation timeout when attempting to contact www.slashdot.org"

(www.slashdot.org is sure an example).

Comment 3

[Keyser Sose]

*** This bug has been marked as a duplicate of 28586 ***

Comment 4

[Jesse Ruderman]

> And another problem related : the popup shown blocks all the other windows
> downloading, while it should only block the window it is related to.

That's probably bug 74331, "modal alert dialog in any window blocks necko for 
all windows".

Comment 5

[benc]

I'm reopening this, and I'm and my inclination is that it will end up invalid 
after some discussion about the actual order of events. Here's why: 

The other mentioned reports (bug 28586 and bug 74331) refer to how the error 
should be handled.

What the reporter wants is to be able to start a transaction while physically 
disconnected from the network, and have it work if the network comes up before 
the application decides to error. In other words, they want NO error to occur.

Although the overall requested behavior might be something reasonsable, I do not 
know if that is what is really going on. This also maybe something that turns 
out to be OS dependent.

Much more analysis is needed her, and the burden of proof is high, (do we know 
the DNS server actually gave the IP address back to the browser and the error 
occurred anyhow?)

Comment 6

[Thibault G.]

The problem here is that Mozilla seems to create the error popup
only when it receives the ip address ... which is quite weird !

I believe that because I've "listened" the network using tcpdump,
and the popup appears just when the DNS answer arrives.
But maybe I'm wrong.

Comment 7

[benc]

mass move, v2.
qa to me.

Comment 8

[Keyser Sose]

Marking NEW.

Comment 9

[Dwayne]

Confirmed on Build 2001-06-09-20, Win2K

OS should be changed to all.
This can happen in either Mail/News or browser.

After losing an internet connection (most occurring on dialup), Mozilla goes
haywire and, at least for me, pops up several "Failed to connect to server."
messages in succession.

Marking my vote!

Comment 10

[Oliver Klee]

-->OS=All

Comment 11

[[e-mail]]

Dwayne:

If this bug is going to go anywhere, I think it should stay Linux only.

This bug is also very specific in the breakage and the requested fix.

There are many other bugs that sound similar, that are probably what you really
want. Can you look for a dupe or create a new bug with your steps for Windows?

I've started to mark these bugs up with a "Conn:" string in the summary and am
writing a new test case for this area (General connectivity). 

Comment 12

[Dwayne]

Well, I've looked at a couple but this one seems to match it best.  Let's hear
from others out there what their take is.  If it seems I may have a separate
bug, I will be glad to file one.

But I can't find anything in the original description that *doesn't* match what
I see.  At the same time, I noticed a similar (and perhaps separate bug) in
MailNews.  This may be what you think qualifies as a separate issue.

To me, it seems that losing your internet connection (whether it be dial-up or
otherwise) causes this error to happen, whatever specific cause it may be.

Comment 13

[benc]

Dwayne, you should give yourself credit for correctly describing the generic
problem first.

This person is going online at a specific moment while running a local DNS
nameserver. This is pretty complicated, and we have to solve the more basic
connection problems first before we can really address this.

Comment 14

[Dwayne]

So therefore should I file a separate bug and make this bug dependent on it?  I
honestly think this is a side effect bug, not a dependent bug.  (Difference
being there's *no* way to fix the first bug without fixing the second as well --
a good thing of course)

I will follow more knowledgeable superiors' directives.  :)

Comment 15

[benc]

Just a new bug. Problems in this area are scattered all over bugzilla, so
keeping one problem per bug is ideal at this stage.

Comment 16

[Dwayne]

Created new bug 86192.  This bug is now dependent on 86192.  Added original
reporter and Benc as CC for that bug for ease of reference.

Comment 17

[Dwayne]

Ooops!

This is dependent on bug 86912.  Sorry for the spam and typo.

Comment 18

[Asa Dotzler [:asa]]

Bugs targeted at mozilla1.0 without the mozilla1.0 keyword moved to mozilla1.0.1 
(you can query for this string to delete spam or retrieve the list of bugs I've 
moved)

Comment 19

[Doug Turner (:dougt)]

moving neeti's futured bugs for triaging.

Comment 20

[benc]

RESOLVED/WFM:
If this still happens, the reporter, or anyone else who is running in Linux w/ a
local DNS server should REOPEN. Everyone else, new bug please.

In general, there seem to be few complaints about mozilla recovering from a
network disconnect;re-connect set of events.

In this case, a local DNS server and Mozilla are cut off by the reconnect. When
the connection is re-established, Mozilla then fails to connect to the IP
address returned by the local server.

The point of failure seems to be the the mozilla using the DNS server's
response, and my guess is the local DNS server is giving some abnormal response
that confuses mozilla.

Since there is no DNS logging or analysis from other clients (nslookup, wget,
etc), or a DNS isolated test (IP address only), this seems to be the most
resonable interpretation.

Comment 21

[John Unruh]

Verified.