Author Topic: firefox + java applet == DNS madness  (Read 1054 times)

Offline gilado

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firefox + java applet == DNS madness
« on: February 11, 2010, 01:22:33 AM »
I have a web site that uses a java applet.  I can access it over the public network (through a firewall), or over a vpn (that goes through the same firewall.)  The difference is what IP address I use.

When I access the website over the public address all is well. The applet starts and communicates with the back end etc.

When I access it over the VPN the applet downloads but then the browser freezes. Wireshark shows it (or the applet) sends reverse DNS queries at a rapid fire rate looking for the PTR of the internal IP address of the server. It get a response but does not seem to like it.

Back to using the public address, it still sends a reverse DNS query and seems to like the answer.

I am pretty sure this is new behavior

Firefox 3.5.5
Java Plug-in 1.6.0_17
Using JRE version 1.6.0_17-b04 Java HotSpot(TM) Client VM

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I run virtual box on the same machine and in it WinxXP with Firefox and Java, access the same website using the same IP address through the same vpn and all works well.

Firefox 3.6
Java 1.6.0_18-b07

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Is that a known problem, is there a setting to tell FF or Java not to spam the net with useless DNS queries



Offline pstranger

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Re: firefox + java applet == DNS madness
« Reply #1 on: February 11, 2010, 02:38:31 AM »
Does the DNS-server answer to the same port of your web-server? I never worked with Wireshark but only with tcpdump in command line. Try to record successful session with numeric addresses and ports only  (-nn option). If you wish you can place results here.