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Server Behind Firewall Question (SOCKS?)

Started by January 24, 2004 02:12 PM
1 comment, last by phillymac 21 years ago
Help! I have a very simple pair of programs. The first is a UDP server that listens on a port for an incoming UDP message and sends back a quick reply. The second is a UDP client that sends a UDP message to a specified IP address/port number, and gets the reply back from the server. This worked okay when I used two computers on a LAN. It also worked across the internet when the computer running the server switched off the firewall. The firewall in question is ZoneAlarm, by the way. But when the server computer had the firewall activated, it wouldn''t work. I''ve tried to work out the solution from searching the web and reading this forum, but I''ve come up short. My questions are: 1) Occationally, when running certain programs, my firewall alerts me that "program XXX is running as a server", and I can either allow it or prevent it from doing that. I expected my UDP Server program to have the same effect on the firewall, but it didn''t. What can I do (as a programmer) to let the firewall know that a program is attempting to listen on a port? 2) During my research I came across SOCKS. (I happen to be using Java, BTW). I found a snippet of code that shows how to set the socksProxyPort and socksProxyHost system properties. I tried that on the server program and it didn''t seem to have any effect. Should it be used on the server program or on the client? Is this the correct way to alert the firewall that I want to run a server? 3) How the flip do I manually tell ZoneAlarm to open a port? 4) Anything else I should know?? Thanks a million!
Zonealarm can allow certain programs unfettered access to the net. Also at the highest level of protection on zone alarm it blocks UDP traffic, only at them medium or low level is udp traffic allowed.

Also make sure your not using a NAT, as they usually have built in firewalls as well.

Good Luck.
-ddn
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Thanks for the info.

I think I''m coming to the realisation that SOCKS is a massive red herring.

I think the thing that threw me is that when I''m using Java, the executable name is always ''java'' and not the program I''m actually executing. ''java'' was already an entry on Zonealarm so there was no new alert.

I still don''t know if it''s working or not as I haven''t been able to raise my buddy to try it out.

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