Re: Different external IP address for different "show my IP" pages!!!

On 9/21/2010 11:46 AM, Elton wrote:
> Hi!
> I have a DSL connection with dynamic IP.
> My problem is that it seems that different pages that show my external
> IP, display different results.
> For example:
> showip.net shows X.Y.Z.84
> showmyip.com.ar shows X.Y.Z.86
> mediacollege.com/internet/utilities/show-ip.shtml shows X.Y.Z.3
> whatismyip.com shows X.Y.Z.116
> showmyip.com shows X.Y.Z.3 (this time is the same
> result as one of the pages above)
> the No-IP DUC shows X.Y.Z.84
>
> Of course the X Y Z don't change.
> So it seems like for different pages or requests my ISP assigns me
> different IPs or something, I don't really understand it.
>
> Initially I wanted to make my home computer a small web server (nginx
> listening on port 6789) that could be accessible from the
> internet and since my IP is dynamic I tried DYNDNS (with no result)
> and now No-IP (with no result, too).
> I added the correct entries for port forwarding in Advanced -> NAT ->
> Virtual Server in my ZTE ZXDSL 831II modem/router (fireware version
> ZXDSL 831IIV7.5.0a_Z29_AL1) but still couldn't access my web server
> neither from the DynDNS host or the No-IP host, so I slowly am giving
> up to the idea of running a web server in my home pc.
>
> But I still am curious to learn more about networks and to understand
> why the above problem (the different WAN IPs problem) happens!
>
> So why does that happen?
> Is it some kind of technique used by ISPs to distribute requests or
> something?!?!?

Were you trying to run the Dynamic DNS program/service directly from
your PC as I suspect or were you using/activating the built in Dynamic
DNS feature built into your router?

Try using the router option and see if that clears things up for you as
it should allow you to actually point it to a specific address on your
LAN, but you should assign that PC a fixed IP outside the range of your
router's DNS server, but in the same subnet.

On Tue, 21 Sep 2010 15:58:12 -0500, GlowingBlueMist
<(E-Mail Removed)> wrote:

>On 9/21/2010 11:46 AM, Elton wrote:
>> Hi!
>> I have a DSL connection with dynamic IP.
>> My problem is that it seems that different pages that show my external
>> IP, display different results.
>> For example:
>> showip.net shows X.Y.Z.84
>> showmyip.com.ar shows X.Y.Z.86
>> mediacollege.com/internet/utilities/show-ip.shtml shows X.Y.Z.3
>> whatismyip.com shows X.Y.Z.116
>> showmyip.com shows X.Y.Z.3 (this time is the same
>> result as one of the pages above)
>> the No-IP DUC shows X.Y.Z.84
>>
>> Of course the X Y Z don't change.
>> So it seems like for different pages or requests my ISP assigns me
>> different IPs or something, I don't really understand it.
>>
>> Initially I wanted to make my home computer a small web server (nginx
>> listening on port 6789) that could be accessible from the
>> internet and since my IP is dynamic I tried DYNDNS (with no result)
>> and now No-IP (with no result, too).
>> I added the correct entries for port forwarding in Advanced -> NAT ->
>> Virtual Server in my ZTE ZXDSL 831II modem/router (fireware version
>> ZXDSL 831IIV7.5.0a_Z29_AL1) but still couldn't access my web server
>> neither from the DynDNS host or the No-IP host, so I slowly am giving
>> up to the idea of running a web server in my home pc.
>>
>> But I still am curious to learn more about networks and to understand
>> why the above problem (the different WAN IPs problem) happens!
>>
>> So why does that happen?
>> Is it some kind of technique used by ISPs to distribute requests or
>> something?!?!?
>
>Were you trying to run the Dynamic DNS program/service directly from
>your PC as I suspect or were you using/activating the built in Dynamic
>DNS feature built into your router?
>
>Try using the router option and see if that clears things up for you as
>it should allow you to actually point it to a specific address on your
>LAN, but you should assign that PC a fixed IP outside the range of your
>router's DNS server, but in the same subnet.

Suspected typo...that last line should read "outside the range of your
router's DHCP server..."

On Tue, 21 Sep 2010 16:13:31 -0700 (PDT), Elton <(E-Mail Removed)>
wrote:

>> Try using the router option and see if that clears things up for you as
>> it should allow you to actually point it to a specific address on your
>> LAN, but you should assign that PC a fixed IP outside the range of your
>> router's DNS server, but in the same subnet.
>
>I was running the Dynamic DNS program/service.
>My router has a builtin option for Dynamic DNS in Advanced -> NAT ->
>Dynamic DNS but it doesn't work.
>This page appears:
>------------------------------------------------------------------------------
>Dynamic DNS
>
>This page allows you to provide Internet users with a name (instead of
>an IP address) to access your virtual servers. This ADSL router
>supports dynamic DNS service provided by the provider ' http://www.dyndns.org',
>or 'http://www.tzo.com'. Please register this service at these
>providers first.
>
>Hostname Username Service Interface Remove
>
> | Add | | Remove | (buttons)
>------------------------------------------------------------------------------
>But when I click Add a blank page appears so the option does not work.
>I have also reserved the IP for my web server pc in the Advanced ->
>LAN -> DHCP Server.

As someone else pointed out, you're not likely going to be able to get
this to work because of the double NAT situation.

On 9/21/2010 5:14 PM, Char Jackson wrote:
> On Tue, 21 Sep 2010 15:58:12 -0500, GlowingBlueMist
> <(E-Mail Removed)> wrote:
>
>> On 9/21/2010 11:46 AM, Elton wrote:
>>> Hi!
>>> I have a DSL connection with dynamic IP.
>>> My problem is that it seems that different pages that show my external
>>> IP, display different results.
>>> For example:
>>> showip.net shows X.Y.Z.84
>>> showmyip.com.ar shows X.Y.Z.86
>>> mediacollege.com/internet/utilities/show-ip.shtml shows X.Y.Z.3
>>> whatismyip.com shows X.Y.Z.116
>>> showmyip.com shows X.Y.Z.3 (this time is the same
>>> result as one of the pages above)
>>> the No-IP DUC shows X.Y.Z.84
>>>
>>> Of course the X Y Z don't change.
>>> So it seems like for different pages or requests my ISP assigns me
>>> different IPs or something, I don't really understand it.
>>>
>>> Initially I wanted to make my home computer a small web server (nginx
>>> listening on port 6789) that could be accessible from the
>>> internet and since my IP is dynamic I tried DYNDNS (with no result)
>>> and now No-IP (with no result, too).
>>> I added the correct entries for port forwarding in Advanced -> NAT ->
>>> Virtual Server in my ZTE ZXDSL 831II modem/router (fireware version
>>> ZXDSL 831IIV7.5.0a_Z29_AL1) but still couldn't access my web server
>>> neither from the DynDNS host or the No-IP host, so I slowly am giving
>>> up to the idea of running a web server in my home pc.
>>>
>>> But I still am curious to learn more about networks and to understand
>>> why the above problem (the different WAN IPs problem) happens!
>>>
>>> So why does that happen?
>>> Is it some kind of technique used by ISPs to distribute requests or
>>> something?!?!?
>>
>> Were you trying to run the Dynamic DNS program/service directly from
>> your PC as I suspect or were you using/activating the built in Dynamic
>> DNS feature built into your router?
>>
>> Try using the router option and see if that clears things up for you as
>> it should allow you to actually point it to a specific address on your
>> LAN, but you should assign that PC a fixed IP outside the range of your
>> router's DNS server, but in the same subnet.
>
> Suspected typo...that last line should read "outside the range of your
> router's DHCP server..."
>
Yep, as suspected it was a typo.

On 9/21/2010 7:44 PM, Char Jackson wrote:
> On Tue, 21 Sep 2010 16:13:31 -0700 (PDT), Elton<(E-Mail Removed)>
> wrote:
>
>>> Try using the router option and see if that clears things up for you as
>>> it should allow you to actually point it to a specific address on your
>>> LAN, but you should assign that PC a fixed IP outside the range of your
>>> router's DNS server, but in the same subnet.
>>
>> I was running the Dynamic DNS program/service.
>> My router has a builtin option for Dynamic DNS in Advanced -> NAT ->
>> Dynamic DNS but it doesn't work.
>> This page appears:
>> ------------------------------------------------------------------------------
>> Dynamic DNS
>>
>> This page allows you to provide Internet users with a name (instead of
>> an IP address) to access your virtual servers. This ADSL router
>> supports dynamic DNS service provided by the provider ' http://www.dyndns.org',
>> or 'http://www.tzo.com'. Please register this service at these
>> providers first.
>>
>> Hostname Username Service Interface Remove
>>
>> | Add | | Remove | (buttons)
>> ------------------------------------------------------------------------------
>> But when I click Add a blank page appears so the option does not work.
>> I have also reserved the IP for my web server pc in the Advanced ->
>> LAN -> DHCP Server.
>
> As someone else pointed out, you're not likely going to be able to get
> this to work because of the double NAT situation.
>

Sorry about the prior typo.

Anyway two things come to mind. One is to verify your browser is not
running an anti-script module, as in Firefox with NoScript. If you are
you need to allow the web site (your modem/router) or at least the IP
address of your router to use them or possible blank screens may happen.
For example my D-Link 2640 modem/router works on some pages but not
others with Java Scripts blocked as they used scripts to display some of
the info.


The other thing might be to use the option to reset the router back to
default and start over. This time with just the minimum changes needed
in order to get it online, like account settings and such.

Then verify the DHCP range assigned to your lan is not the entire
subnet. Limit it to about 50 address. Since most ISP's or rather
routers assign the lowest address to the router I usually limit my
values to 50 and leave 51 to 254 for fixed IP's, if any, but you can
start at say 51 and go higher and leave the lower numbers for fixed IP's
if you like.

After the above has been done and the router rebooted, try the Dynamic
DNS page of the router again.

By the way, which ISP are you using for your internet connection? We
might be able to get more specific depending on the provider in question.

On Wed, 22 Sep 2010 18:03:36 -0700 (PDT), Elton <(E-Mail Removed)>
wrote:

>Why should I limit my DHCP's server range when I have only 2 PCs in my
>home network that always get assigned their predefined IPs in the DHCP
>server's reserved IP list, and when I don't need the other IPs because
>my network has always only 2 desktop PCs?
>Is there any technical reason?

I forget now, but didn't this whole sub-thread get started because you
wanted to assign an IP address that wouldn't change to your web
server? One bit of advice was to assign an address outside of your
DHCP server range, but you couldn't because your entire subnet was
dedicated to DHCP. I think that's how all of this got started, and as
you've seen, there are several ways to approach the problem of
assigning IP's, each about as good as another as long they meet your
needs.

On Wed, 22 Sep 2010 18:22:20 -0700 (PDT), Elton <(E-Mail Removed)>
wrote:

>About the initial question for the different external IPs: could we
>safely assume that my ISP has a double NAT configuration or is it
>something else that causes this behaviour?

I thought you verified that the other day. From your router's
perspective, its WAN IP is in the 10.x.x.x space, and that address
gets NAT'd to a routable IP by your ISP. That's double NAT.

On 9/22/2010 8:22 PM, Elton wrote:
> About the initial question for the different external IPs: could we
> safely assume that my ISP has a double NAT configuration or is it
> something else that causes this behaviour?

It sounds like either double NAT or your host ISP is using some sort of
address scrambler in their router to ensure you can not host your own
server.

One way to usually identify double NAT is to open a command window, also
known as command.com in older versions of Windows.

With the command window open, try doing a route trace to a large
commercial organization, as in "tracert www.google.com", minus the quote
marks, and check the results.

If you see an address starting with any combination of the following
other than the very first entry then you are experiencing a double NAT
problem as these IP values are restricted from being routed directly
over the internet.

10.0.xxx.xxx
172.16.xxx.xxx
192.168.xxx.xxx

If not then the ISP must have something in your path that they are using
to actively randomize the route of your inbound address as a means of
blocking you from having a web server.

Usually I have seen that in locations where the host country is paranoid
about people running their own unmonitored web sites, like China or
North Korea.

I've run out of ideas and will bow out of the discussion so others can
be heard...

On 9/23/2010 12:15 AM, Char Jackson wrote:
> On Wed, 22 Sep 2010 18:22:20 -0700 (PDT), Elton<(E-Mail Removed)>
> wrote:
>
>> About the initial question for the different external IPs: could we
>> safely assume that my ISP has a double NAT configuration or is it
>> something else that causes this behaviour?
>
> I thought you verified that the other day. From your router's
> perspective, its WAN IP is in the 10.x.x.x space, and that address
> gets NAT'd to a routable IP by your ISP. That's double NAT.
>

I guess I'm confused by what is going on here. It would seem that the
router should be seeing an address that can be accessed directly by any
other computer on the internet.

Certainly, if a user goes to a site like http://grc.com and run his
Shields Up scan, it must have an IP address for your computer that it
can access. The OP might try that, and see if that scan would work for
him or not.

Another site of interest (and maybe he has already tried this one) is
http://checkip.dyndns.com.

If, over time, he has sent himself emails, he might look at the headers
in them and see what the IP addresses are that show up there.

I get an IP address (well, my router does) via DHCP from my ISP. I can
go into my router and view the connections status:
IP Address 70.100.XXX.25
Subnet Mask 255.255.224.0
Default Gateway 70.100.128.1
DHCP Server 70.100.128.1
DNS Server 8.8.8.8 4.2.2.4
Lease Obtained Thursday Sep 23 01:11:50 2010
Lease Expires Thursday Sep 23 13:11:50 2010
Note in my case, the IP address is obtained for a 12 hour period. Half
way thru that, the router will request a renewal for another 12 hours.
That is so my router always has a valid IP address for replies coming
back in. If that IP were to change part way thru a session, then some
replies coming back might get directed to an IP that no longer existed.

The IP address I get is a dynamic IP -- subject to change at any time.
But, over the years the only time it has changed is when the server at
the other end of the DSL line was rebooted (which used to happen several
times a day), or when I changed routers and didn't update the MAC in
them. As it is, I have had the same IP address now for several years.

I don't know if the OP has the ability, but it might be interesting if
he were to sniff the traffic between his modem and his router. I can do
that, because my DSL modem is a separate unit from my router. Newer DSL
modems have a router built in, and that cuts down on the versatility of
things. (For one thing, you can't hang another router on it -- easily
anyhow.)

The use of the IP address in the 10.x.x.x. range is interesting tho.
Here, if I try a TRACERT to 10.0.0.4, it shows a trace to the router,
then to the ISP gateway, then loops between two other addresses at the
ISP. I would have assumed that address would never escape my LAN -- but
the router apparently passes it on out to the DSL modem which runs in
bridged mode.

If I try the TRACERT with 172.16.0.4, the same thing happens, except the
looping at the final destination pair does not happen (it just times out).

I guess, on the other side of the coin, look at the good side of having
a constantly changing IP address. That is like having an anonymizer
service built in -- nobody can really be tracking what you do and where
you visit on the web!

....Bob

On 9/23/2010 9:12 AM, Elton wrote:
>> I guess I'm confused by what is going on here. It would seem that the
>> router should be seeing an address that can be accessed directly by any
>> other computer on the internet.
>
> The router itself has an external WAN IP of the 10.x.x.x range.
> So the problem is that I have no information what's going on between
> my router, ISPs router and the internet or what processing gets done
> to the TCP IP packets in every route-step inside the ISP, sent/
> received between my router and the internet.
> I have noticed that my router's WAN IP of range 10.x.x.x, changes
> every time the router is restarted I think.
>
>
>> Certainly, if a user goes to a site like http://grc.com and run his
>> Shields Up scan, it must have an IP address for your computer that it
>> can access. The OP might try that, and see if that scan would work for
>> him or not.
>
> An all service ports scan in the Shields Up page, results in 1052
> closed ports, 0 opened ports and 4 stealth ports which are 22, 80, 443
> and 646.
> Another scan around 2 hours later in the Shields Up page, results in a
> different IP scanned (the first one was X.Y.Z.84 and now the second
> one is X.Y.Z.11) and only 2 stealth ports which are 22 and 646. All
> the other ports are closed and no port is opened.
> A local scan to my router's WAN IP with the SuperScan 4.0 program in
> the 1-1060 port range, results in 6 opened TCP ports which are 21, 23,
> 80, 110, 443 and 995.
>
>> I don't know if the OP has the ability, but it might be interesting if
>> he were to sniff the traffic between his modem and his router. I can do
>> that, because my DSL modem is a separate unit from my router. Newer DSL
>> modems have a router built in, and that cuts down on the versatility of
>> things. (For one thing, you can't hang another router on it -- easily
>> anyhow.)
>
> I don't think I can do that because my DSL modem is also a router and
> they are the same unit.
> Can I sniff the traffic between my router and the ISP, or at least log
> the sent and received packets in the router?
> I don't think I could understand anything from the sniffing if it is
> possible to be done, but anyway just for experimentation.
>
>> The use of the IP address in the 10.x.x.x. range is interesting tho.
>> Here, if I try a TRACERT to 10.0.0.4, it shows a trace to the router,
>> then to the ISP gateway, then loops between two other addresses at the
>> ISP. I would have assumed that address would never escape my LAN -- but
>> the router apparently passes it on out to the DSL modem which runs in
>> bridged mode.
>
>> If I try the TRACERT with 172.16.0.4, the same thing happens, except the
>> looping at the final destination pair does not happen (it just times out).
>>
>
> This is the status overview on my router's page:
> LAN IP Address 192.168.1.1
> Default Gateway 10.101.0.1
> Primary DNS Server 10.1.254.1
> Secondary DNS Server 10.1.2.2
>
> This is a TRACERT to google.com:
> ----------------------------------------------
> C:\Documents and Settings\User>tracert google.com
>
> Tracing route to google.com [209.85.135.103]
> over a maximum of 30 hops:
>
> 1 1 ms<1 ms<1 ms 192.168.1.1
> 2 41 ms 43 ms 42 ms 10.101.0.1
> 3 58 ms 60 ms 59 ms 10.1.249.1
> 4 * * * Request timed out.
> 5 86 ms * * 62.75.3.29
> 6 168 ms * 143 ms 62.75.4.129
> 7 147 ms 145 ms 143 ms 62.75.4.214
> 8 138 ms 137 ms 145 ms 74.125.50.113
> 9 * * 144 ms 209.85.255.176
> 10 145 ms 148 ms 142 ms 209.85.248.248
> 11 * 151 ms 147 ms 209.85.241.187
> 12 149 ms 159 ms 161 ms 72.14.239.54
> 13 156 ms 148 ms 151 ms mu-in-f103.1e100.net [209.85.135.103]
>
> Trace complete.
> ----------------------------------------------
>
>
>> I guess, on the other side of the coin, look at the good side of having
>> a constantly changing IP address. That is like having an anonymizer
>> service built in -- nobody can really be tracking what you do and where
>> you visit on the web!
>
> That's not true. Even though my IP changes constantly for different
> pages, I always get tracked by bans, blocks, and can't donwload for
> free on rapidshare, hotfile, megaupload, etc. when I hav previously
> downloaded a large quantity/size of files.

I've gone over your previous posts, and I guess I missed a lot :-(

One thing I noticed, your ISP is running PPPoE -- and that is something
I hadn't really paid much attention to before. I briefly have looked it
up, but there is a lot to it that I don't know. Maybe that is where
some of the other more knowledgeable people here might help you.

If I understand it correctly, every time you go to a site, it creates a
'session' -- and each session probably results in what appears to be a
different IP address for you. The 10.0.x.x addresses your router is
showing probably are valid addresses in a LAN for your ISP. When you
send a packet out, it gets 'encapsuled' in an 'envelope packet', sent to
your ISP, where it is sent on using an IP address for that session.

In looking at some of the messages you have posted, almost all seem to
be coming from 79.106.109.XXX, with that last XXX varying all over the
place. Very seldom the same twice! But you wouldn't be able to use any
of those for inbound traffic, since they are getting used over and over
for different customers.

Unless you can get a static IP from your ISP (and lots of luck for
that!) I am not sure how to solve your problem. I think you mentioned
you had already talked to their support people and had struck out. That
seems to be a world wide problem, the people answering the telephones
for support have a fixed list of questions to ask, and hoops for you to
jump thru, and assume if those don't fix the problem it, can't be fixed.

Do some research on the PPPoE and see if any of it makes sense with what
you see.

And, changing your LAN settings I sincerely don't think will have any
effect on what is going on. I run a mix of static and dynamic IPs on my
LAN, but with the router always handing out the same IP via DHCP to the
dynamically assigned devices. I think you mentioned you do the same,
and that is good.

The other thought -- depending upon what type of server you want to get
going, does your ISP offer any web space? My ISP has web space, and
also FTP space, available for each mailbox account. However, they limit
very closely what you can run in a web server. That isn't like having
something on your own computer where you can easily change things, but
it's better than nothing.

....Bob