[WEB4LIB] Private IP and firewall

[Yi Kong]

Thank you, everybody.  Finally we solved the problem by giving external IP range to the vender.  I might be wrong here, but I think private IP need to convert to a range of IP outside can see.  Like our libraries, we use class C private IP, around 100 of them, but when they pass through firewall or web server, they convert to 8 IP's, which are regular IP's and provided by ISP.  Vender list those IP at their table, the communication path is established.  

-----Original Message-----
From:	Josh Kuperman [SMTP:sar_kuper at sals.edu]
Sent:	Wednesday, February 24, 1999 9:29 AM
To:	ykong at kenosha.lib.wi.us; web4lib at webjunction.org
Subject:	Re: [WEB4LIB] Private IP and firewall

At 01:11 PM 2/23/99 -0800, you wrote:
>Hi, All,  Our libraries have a problem to access vender's database from Internet by PC's with private IP addresses.  We can access the database from our main library, where PC's are using regular IP.  Although we ask this vender put those private IP on th
>eir list, access was still denied.  Technician there thinks it is our firewall's interpretation problems.


Proxy-servers can use their IP addresses to retrieve websites for a private network. Simply go through a proxy and then the proxy server would retrieve the web page. One freely available proxy server is Squid running under Linux. It can do a lot more as well. There are many proxy servers available, the best choice should probably be made by someone who understands your network. Since your technician didn't mention a proxy server you may have other problems.

There is the real danger of misconfiguring the proxy server so that anyone who knows about it, from inside or outsided your network can use it. If you have a decent firewall this may not be a problem, but you will probably have to ask your firewall vendor hwo to set things up.

--
Josh Kuperman        Saratoga Springs Public Library
sar_kuper at sals.edu   49 Henry St  
518.584.7860x211     Saratoga Springs, NY 12866
http://www.library.saratoga.ny.us