different ip addresses returned by different websites

[Ben]

Hi all,

I'm posting this to comp.lang.php and comp.protocols.tcp-ip.

I'm quite new to php. I made a simple test page in php with
"_SERVER[REMOTE_ADDR]" and "_SERVER[REMOTE_PORT]" server variables. I
uploaded my page in tripod.co.uk as they provide free php hosting. The
above variables gave me an ip address and port number. To double
check, I tried few other websites such as www.whatismyip.com and
http://checkip.dyndns.org. The first one gave me a different ip from
the one shown by my test page. The second one, however, showed exactly
the same ip address. I don't know what's going on? Isn't it meant to
be just ONE ip?

I am behind Wingate proxy which is on another pc on my home LAN. I use
dial-up to connect to ISP.

Now about "_SERVER[REMOTE_PORT]". In my test page, after few
refreshments, the REMOTE_PORT number also chages to new number. Why is
this? As far as I understand, "REMOTE_PORT" is the port my computer
uses to communicate with the web server. So every time I refresh, does
it assign a random port number?

Thanx
Ben

[Lev Walkin]

Ben wrote:

Hi all,

I'm posting this to comp.lang.php and comp.protocols.tcp-ip.

I'm quite new to php. I made a simple test page in php with
"_SERVER[REMOTE_ADDR]" and "_SERVER[REMOTE_PORT]" server variables. I
uploaded my page in tripod.co.uk as they provide free php hosting. The
above variables gave me an ip address and port number. To double
check, I tried few other websites such as www.whatismyip.com and
http://checkip.dyndns.org. The first one gave me a different ip from
the one shown by my test page. The second one, however, showed exactly
the same ip address. I don't know what's going on? Isn't it meant to
be just ONE ip?
Noone guaranteed you that, right? Maybe, there is a NAT somewhere
on the way to your website (or even a reverse NAT near the free PHP hosting).
I am behind Wingate proxy which is on another pc on my home LAN. I use
dial-up to connect to ISP.

Now about "_SERVER[REMOTE_PORT]". In my test page, after few
refreshments, the REMOTE_PORT number also chages to new number. Why is
this? As far as I understand, "REMOTE_PORT" is the port my computer
uses to communicate with the web server. So every time I refresh, does
it assign a random port number?

Yes. It is extremely likely that the each refresh makes another connection
to the remote site, picking the next available port number. It is usually
not random (it's sequential), although it well may be under your OS.

--
Lev Walkin
vl*@lionet.info

[Ben]

Lev Walkin <vl*@lionet.info> wrote in message news:<2l************@uni-berlin.de>...

Ben wrote:

Hi all,

I'm posting this to comp.lang.php and comp.protocols.tcp-ip.

I'm quite new to php. I made a simple test page in php with
"_SERVER[REMOTE_ADDR]" and "_SERVER[REMOTE_PORT]" server variables. I
uploaded my page in tripod.co.uk as they provide free php hosting. The
above variables gave me an ip address and port number. To double
check, I tried few other websites such as www.whatismyip.com and
http://checkip.dyndns.org. The first one gave me a different ip from
the one shown by my test page. The second one, however, showed exactly
the same ip address. I don't know what's going on? Isn't it meant to
be just ONE ip?

Noone guaranteed you that, right? Maybe, there is a NAT somewhere
on the way to your website (or even a reverse NAT near the free PHP hosting).

So how do I determine my actual IP address? Is it the one shown by PHP
hosting or the one shown by www.whatismyip.com? Or do these 2 IP
addresses map to the same thing (something like symbolic link under
Linux filesystem)?

I am behind Wingate proxy which is on another pc on my home LAN. I use
dial-up to connect to ISP.

Now about "_SERVER[REMOTE_PORT]". In my test page, after few
refreshments, the REMOTE_PORT number also chages to new number. Why is
this? As far as I understand, "REMOTE_PORT" is the port my computer
uses to communicate with the web server. So every time I refresh, does
it assign a random port number?

Yes. It is extremely likely that the each refresh makes another connection
to the remote site, picking the next available port number. It is usually
not random (it's sequential), although it well may be under your OS.

[Michael Austin]

Ben wrote:

Lev Walkin <vl*@lionet.info> wrote in message news:<2l************@uni-berlin.de>...

Ben wrote:

Hi all,

I'm posting this to comp.lang.php and comp.protocols.tcp-ip.

I'm quite new to php. I made a simple test page in php with
"_SERVER[REMOTE_ADDR]" and "_SERVER[REMOTE_PORT]" server variables. I
uploaded my page in tripod.co.uk as they provide free php hosting. The
above variables gave me an ip address and port number. To double
check, I tried few other websites such as www.whatismyip.com and
http://checkip.dyndns.org. The first one gave me a different ip from
the one shown by my test page. The second one, however, showed exactly
the same ip address. I don't know what's going on? Isn't it meant to
be just ONE ip?

Noone guaranteed you that, right? Maybe, there is a NAT somewhere
on the way to your website (or even a reverse NAT near the free PHP hosting).

So how do I determine my actual IP address? Is it the one shown by PHP
hosting or the one shown by www.whatismyip.com? Or do these 2 IP
addresses map to the same thing (something like symbolic link under
Linux filesystem)?

I am behind Wingate proxy which is on another pc on my home LAN. I use
dial-up to connect to ISP.

Now about "_SERVER[REMOTE_PORT]". In my test page, after few
refreshments, the REMOTE_PORT number also chages to new number. Why is
this? As far as I understand, "REMOTE_PORT" is the port my computer
uses to communicate with the web server. So every time I refresh, does
it assign a random port number?

Yes. It is extremely likely that the each refresh makes another connection
to the remote site, picking the next available port number. It is usually
not random (it's sequential), although it well may be under your OS.

is the IP always different or only sometimes different -- and are you on DSL or
Cable or Dialup?

port number assignments are dynamic and will change with each connection - and a
refresh is a new connection.

--
Michael Austin.
Consultant - Available.
Donations welcomed. Http://www.firstdbasource.com/donations.html
:)

[Ben]

Michael Austin <ma*****@firstdbasource.com> wrote in message news:<1_*****************@newssvr23.news.prodigy.c om>...

Ben wrote:

Lev Walkin <vl*@lionet.info> wrote in message news:<2l************@uni-berlin.de>...

Ben wrote:

Hi all,

I'm posting this to comp.lang.php and comp.protocols.tcp-ip.

I'm quite new to php. I made a simple test page in php with
"_SERVER[REMOTE_ADDR]" and "_SERVER[REMOTE_PORT]" server variables. I
uploaded my page in tripod.co.uk as they provide free php hosting. The
above variables gave me an ip address and port number. To double
check, I tried few other websites such as www.whatismyip.com and
http://checkip.dyndns.org. The first one gave me a different ip from
the one shown by my test page. The second one, however, showed exactly
the same ip address. I don't know what's going on? Isn't it meant to
be just ONE ip?

Noone guaranteed you that, right? Maybe, there is a NAT somewhere
on the way to your website (or even a reverse NAT near the free PHP hosting).
So how do I determine my actual IP address? Is it the one shown by PHP
hosting or the one shown by www.whatismyip.com? Or do these 2 IP
addresses map to the same thing (something like symbolic link under
Linux filesystem)?

I am behind Wingate proxy which is on another pc on my home LAN. I use
dial-up to connect to ISP.

Now about "_SERVER[REMOTE_PORT]". In my test page, after few
refreshments, the REMOTE_PORT number also chages to new number. Why is
this? As far as I understand, "REMOTE_PORT" is the port my computer
uses to communicate with the web server. So every time I refresh, does
it assign a random port number?

Yes. It is extremely likely that the each refresh makes another connection
to the remote site, picking the next available port number. It is usually
not random (it's sequential), although it well may be under your OS.

is the IP always different or only sometimes different -- and are you on DSL or
Cable or Dialup?

IP has always been different.. I am using Dialup. I am behind Wingate
proxy and sharing internet connection.

Ben
port number assignments are dynamic and will change with each connection - and a
refresh is a new connection.