View the Most Wanted LQ Wiki articles.
Go Back > Forums > Linux Forums > Linux - Networking
User Name
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.


  Search this Thread
Old 07-15-2007, 05:11 PM   #1
Registered: Aug 2006
Location: Allahabad,India
Distribution: Fedora Core 5
Posts: 41

Rep: Reputation: 15
how can a host outside a private network know the actual sender's ip ??

hi everyone,
we have a private class B network 172.31 subnetted. To connect to the internet we use some proxy servers connected to a router n then to the Internet.
I am a networking newbie and earlier i thought when a http request is sent using a proxy , the packet might be sent from the other i-face of the router i.e connected to Internet which has some ip other than 172.31 , but when i was browsing i found that it was displaying my private ip address n obviously that one of the router's..

how can they manage to know about a host on a private network??
unaware of much about PHP n web designing,firstly i thought they might be using some applet kind of thing in their HTML source code n know the private ip by running appropriate prog. on the client side.. but even that wasn't true.. here is a segment of the html source of that web page
 <TD class="fontgraysmall" width="65%">
 <span id="Livedemo1_lblIpAddress"
which is simple html n nothing else.. could someone plzz clarify how do they manage to do this??

thanx in advance...

Last edited by rs_vijay; 07-15-2007 at 05:18 PM.
Old 07-15-2007, 05:17 PM   #2
LQ Guru
Registered: Aug 2001
Location: Fargo, ND
Distribution: SuSE AMD64
Posts: 15,733

Rep: Reputation: 657Reputation: 657Reputation: 657Reputation: 657Reputation: 657Reputation: 657
If they displayed your IP address, then they probably are running a java script program in your browser which displays your IP address.

Last edited by jschiwal; 07-15-2007 at 05:19 PM.
Old 07-15-2007, 08:31 PM   #3
Registered: Apr 2004
Distribution: redhat 9.0, fc4, redhat as 4
Posts: 520

Rep: Reputation: 31

this is due to squid configuration. you can block it throught squid. currently i am using windows xp, when i boot linux, i will send you config tag.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Low actual disk throughput over network squisher Linux - Hardware 2 02-11-2007 01:40 PM
Possible? 1 public subnet/1 private; 1 host: traffic out the way it came in? JMCraig Linux - Networking 8 10-17-2005 08:12 PM
Fully Qualified Host Name on a private network Steerpike Linux - Networking 5 12-14-2004 06:48 AM
private network IP 'detected' bulliver Linux - Security 4 10-05-2004 03:03 PM
Mysterious DNS Lookups on private host neiljt Linux - Security 3 08-31-2004 07:31 PM

All times are GMT -5. The time now is 04:40 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration