215302 - DNS server IP is cached and resolv.conf ignored unless mozilla restarted

Status: VERIFIED DUPLICATE of bug 214538

(Core :: Networking, defect)

Description

[Eric W. Bates]

User-Agent:       Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.4) Gecko/20030804
Build Identifier: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.4) Gecko/20030804

This might be related to #190981...  I have discovered that when Mozilla is
started it "learns" the IP of name servers; but after a subsequent dhclient
leases has changed this information, Mozilla continues to attempt to use the
same name server.  This is only a problem when the earlier DNS server cannot be
reached (i.e. it is behind a NAT box) or if the DNS server is refusing queries
because of some ACL.

Reproducible: Always

Steps to Reproduce:
1.Setup a test LAN with a SOHO router using NAT.
2.Plug a machine into the SOHO lan, get a DHCP lease and start up Mozilla
(should work fine)
3.Move the ethernet back to your regular lan in front of the SOHO.
4.Try to load a page for which Mozilla does not already have the IP (e.g. don't
just refresh your current page).
5.Quit Mozilla and restart it. Problem goes away.

Actual Results:  
Host not found.  A scanner (I used ethereal) will show packets going out to the
earlier name server to which there is no route.

Expected Results:  
I don't know enough about the AF_INET libraries to know what is going on.  I
suspect that for some degree of efficiency; Mozilla is doing it's own DNS look
ups? In any case, Mozilla is ignoring the updated information in /etc/resolv.conf

I originally noticed this on my laptop at a customer's site. I have not
confirmed this on any other platform.  However, the problem existed on my older
copy of 1.3.x and persists after I compiled 1.4.2

Comment 1

[Jo Hermans]

This was by design (for security issue 162871), but should be fixed very soon by
bug 205726.

Workaround : click twice on the online/offline icon at the bottom right. That
should clean the DNS-cache. The rest is up to the OS.

*** This bug has been marked as a duplicate of 214538 ***

Comment 2

[benc]

V/dupe.