Just a bit of help needed please !

Hi

I hope someone can help me to understand this problem.

I need to set up my Zoom X5v router with WinXP. I have an internet connection as I'm using the comp at the minute but I just want to get things right as I don't think they are at the minute.

What I need to know :-
1. The IP address that I got from my ISP is a static one and I'll call it 123.456.78.9
but in my network settings in WinXP my TCP/IP shows something like IP Address 10.0.0.200 with a subnet mask 255.255.255.0 and default gateway 10.0.0.2

but why is the IP address that is showing 10.0.0.200 not the one I got from my IP 123.456.78.9

what I really would like is someone to tell me what settings go where in both my router and TCP/IP config or should this just be set to AUTO in WINXP

in a reply from anyone we will call the settings like this

Static IP from ISP just call "A"
Subnet mask call "B"
Default gaeway "C"
Router LAN IP address "D"

Please help.
Many thanks Fizzy

In reply to:

---

1. The IP address that I got from my ISP is a static one and I'll call it 123.456.78.9
but in my network settings in WinXP my TCP/IP shows something like IP Address 10.0.0.200 with a subnet mask 255.255.255.0 and default gateway 10.0.0.2

but why is the IP address that is showing 10.0.0.200 not the one I got from my IP 123.456.78.9

---

Yes. Why. OK, I imagine you think it is your router which has an IP address, and it's your computer also. If that is your mental picture, then please start afresh here.

It is never hosts [ie pc's and routers] which have IP addresses, it is always network interfaces which have the addresses. So your router has a WAN address for the interface to the ISP and a LAN address for the interface to your network. Similarly, a pc will have an IP address on a wired ethernet interface, another on a wireless ethernet interface and another on a dial up modem interface.

So the address from the ISP is taken by the WAN interface of the router and the LAN interface takes 10.0.0.2. Your PC meanwhile takes 10.0.0.200, to be on the same subnet as the LAN interface of the router - it is not enough that they are on the same wires [if we are talking wired ethernet], they must also have addresses which are on the same subnet.

Google on tcp/ip subnet and on subnet mask. The site http://www.tcpipguide.com is quite good IIRC

Thanks for the reply

I know I always get things to work by trial and error but I think this time while I still have a connection to the net I will go and read a bit more.

I just find it strange that no site seems to state that ..... this bit talks to this bit ... so this number should be the same as this number .... and set it all out in pics to help people like me.

I would love examples as it is always better to get it correct in my head that way.

Thanks again PitNicker Cheers

WOW I looked at that link and it just went straight over my head ..... I tried reading a few bits that I thought i WOULD UNDERSTAND but I say again WOW 1600 pages of not very light reading lolol
If anyone has a newbie link to submit I would be grateful as there is NO WAY I could even start into that site without someone with the knowledge sitting beside me and talking me through it.

Thanks again

Try and think of it like this (although not technically correct).

The port on your router that the modem cable plugs into (to connect to the phone line) is given the fixed IP address from your ISP (e.g. 123.456.78.9). This is the external side of the router and uses an IP address that can be seen by the Internet. This way your router can send and receive data to and from the Internet.

On the internal side of the router is your home network (i.e. your computers, printers etc...) and these are plugged into the network ports of the router (or connecting wirelessly). These are all given private IP addresses by the internal side of the router (e.g. 10.0.0.200), which is in the same range as the router's internal address so the home network can all communicate together.
In the process of giving your computers Private IP addresses the router should also configure the DNS server and Default gateway to be the same as the routers address.

So basically we now have two networks which are connected together by the router. This is the whole point of a router; to connect networks together.
When one of your home computers wants to access the Internet it first contacts the router which passes on the data. When data is sent back it is sent to your router which then sends it to the correct computer.
This is what the default gateway part is for. It is so your home computers know where to send data if they need to contact a host not on your internal network.

Make sense?

The real question is if you don't understand all of this, why have you asked for a fixed IP address?
If you are running some program that requires a fixed IP address on one of your home computers you would need to forward certain ports on the router to the internal IP address of that computer.

If the IP address given to you just happens to be fixed and you don't need it for any specific reason I woudn't concern yourself with the fact that it's fixed and not static.

Edited by SSmith (Thu 17-May-07 05:50:02)

Hah, kept you occupied for a while!

The table of contents for that site is http://www.tcpipguide.com/free/t_toc.htm. The relevant topic is IP addressing, about 20% of the way down the page, which leads you to http://www.tcpipguide.com/free/t_IPAddressing.htm. You probably need to look at most of this section to get it in context, but the nub of it for your question is http://www.tcpipguide.com/free/t_IPSubnetAddressingSubnettingConcepts.htm. If you understand that, you should be able to answer your original question.

I find the site good because it is reliable info and it doesn't dumb it down, which can often be misleading and, in the long run, confusing. Nothing else has stuck in my mind as much as this one.

The good thing about TCP/IP is that [by design] you can look at just one topic without needing to know very much about anything else. So, this part is about 30 pages, I think, much less formidable than the whole works.

I think the OP needs to understand the difference between public and private IP addresses, and why they are needed. It's because there aren't enough IP addresses to go around, so for routing inside private networks (which can be either personal or business), we use private addressing, using a range of addresses which are not routable on the public IP network, so they can be used by anyone, and we don't have to worry about two interfaces using the same IP address. This is also the reason why ISP's are reluctant to give out fixed IP addresses to those who don't really need them.

http://en.wikipedia.org/wiki/Private_network

Edited by deleted (Thu 17-May-07 08:25:11)

Thanks again for all your help .... although I think I will not say thanks to PitNicker for giving me a sore head from that site hahahahaha OK Thanks PitNicker I know you were really trying to help.

I did get everything sorted by the way of www.portforward.com as it shows me big pics )) and explains things in a more newbie network type style

So again .... Thanks to you all for the help and see you sometime again !!

Cheers Fizzy

In reply to:

---

although I think I will not say thanks to PitNicker for giving me a sore head from that site hahahahaha OK Thanks PitNicker I know you were really trying to help

---

Ha ha. Next question you ask, I'll point you back to that site.