Java applets work on wired network, but not on wireless

Posted on 2015-01-15
Last Modified: 2015-03-09
We have two similar data collection systems. Each has a web server.  Each web server has menus and some of the selections open Java apps.  When we connect to the web servers by Ethernet cable, the Java applets work fine.  
However, when we are on our wireless network, one web server will run the Java applications and the other will not.  We do get to the home web page with the menus on each, but the Java apps will not.

These are third party systems, so we have limited access to and knowledge of these systems.  The third party is suggesting we are blocking access to the system in question.  We basically don’t block internal traffic.  We did not configure the switch ports from one system differently than the other.  The web server in question appears to have communication of some sort, because we can get to the home screen with menus on both.

Is there something that we should consider that we are missing as to the cause of this?
Question by:tmaususer
  • 9
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Author Comment

ID: 40551067
I let the Java app time out and attached is the error I got.
I forgot to mention I tried some DNS entries that made no difference.  
Java Message

Author Comment

ID: 40551071
Here is the info I get when I click details:

Java Plug-in
Using JRE version 1.8.0_25-b18 Java HotSpot(TM) Client VM
User home directory = C:\Users\tma0258
c:   clear console window
f:   finalize objects on finalization queue
g:   garbage collect
h:   display this help message
l:   dump classloader list
m:   print memory usage
o:   trigger logging
q:   hide console
r:   reload policy configuration
s:   dump system and deployment properties
t:   dump thread list
v:   dump thread stack
x:   clear classloader cache
0-5: set trace level to <n>
ServerName is
LVL 29

Expert Comment

by:Sudeep Sharma
ID: 40551344
Ok, I see that it is an internal website, so I also assume that the wireless device is also internal.

How is the wireless device been setup? Is it on brigde mode or NAT mode.

Most likely it is on NAT mode and your system when connected to wireless is getting altogether a different IP range from what you are getting when it is on LAN/Wired.

So most likely when you are connected on wireless, your system is unable to connect or resolve to the links which are inside the application and hence you are getting errors.

To try fixing it, setup the wireless device on the brigde mode ( i hope you have enough IPs to set on wireless too)

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Author Comment

ID: 40551369
I'm sorry.  I wasn't clear.  The web servers are connected to the network by Ethernet cable.  The wireless devices are simply our laptops.  

Background info - each system has it's own computer with it's own web server.  One is named AOM-Server and the other ANDONMOBLIE.

I did notice this:
the ANDONMOBILE server will append our domain name to itself in DNS.  The other AOM-Server does not have a domain name appended.  Yesterday I tryed manually appending it, but it did not help.  Could the vendor need to add our domain suffix in his websever/computer in question?

About your suggestion - Would this mean the vendor needs to correct his NAT/Bridge within his system?  I don't really have access to his system.  Is this something I should ask him to check?
LVL 29

Assisted Solution

by:Sudeep Sharma
Sudeep Sharma earned 500 total points
ID: 40551596
NAT Bridge is related to the wireless network. so your system admin needs to fix it, if needs to be fixed, which we are not sure right now.

So we need to gather some more information:
In command prompt type:
ping ANDONMOBILE server name and post the out put here.
ping AOM-Server and post the output here.


Author Comment

ID: 40551987
I’m a little confused, and guess I did not give enough info.

The web servers are only accessed by IP address from within the building.  They are both on the same subnet.  People do not view them while offsite.  So, I don’t think traffic from the web server is ever reaching our NAT in the firewall.  I think the traffic is being routed only through the switches.  

I am still stuck on the fact the one system is fine and the other not.  I would lean more towards the issue starting in the web server or computer belonging to the vendor.  Does this hold any merit?

When approved, I can send screenshots of the pings with IP addresses modified.

Author Comment

ID: 40552001
Oh, here is another question.  If we can get to the front web page of both both servers, but the Java applets only work on one of them, could it be some kind of coding in the java or maybe a configuration in that webserver?
LVL 29

Expert Comment

by:Sudeep Sharma
ID: 40552006
By one question:
Within the building do you have wired systems and also have wireless systems?

Are wired systems working fine?
Is the issue related to only wireless systems?


Author Comment

ID: 40552027
When any given laptop is connected by wire, Java apps work from both web servers.
When a laptop is then disconnected from the wire and connected to our wireless network, which is on a different subnet, the java apps work for one web server but not the other.
We have no other network issues at this time.

Author Comment

ID: 40552114
we are able to connect to but web servers wired or wireless.  It's just the java apps that have the issue.

Accepted Solution

tmaususer earned 0 total points
ID: 40645387
The default gateway on the web-server was incorrect.

Author Closing Comment

ID: 40653454
My comment gives the most exact cause.

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