I have Road Runner with a Motorola SBV4200 voice over IP Cable Modem. I am in the process of setting up a Full Featured server with Mandrake 10.1. I am going by these instructions here at LQ: http://www.linuxquestions.org/questi...icle&artid=438

My question is about how an IP address is assigned. Now I have a dyanmic IP address through Road Runner. That ip address changes and gets sent to the modem. Then in turn the modem sends it to a/the computer(s) Now even though I have a dynamic ip address when it is sent to my modem, when my modem sends it to my computer is it a static ip address? What I mean is it the same ip address from the modem to the computer opposed to the dynamic address that the modem recieves? It seems like it would be. I hope I asked that clearly enough. I am a bit lost.

Thanks.

Webwolf

pfffff sorry your question is really confuse.
Usually, DSL works this way :

ISP------(Modem translate signal)-------Computer(public ip, something like 1.2.3.4 but NOT 10.x.x.x or 192.168.x.x)

Now, today, some DSL modems act like router, so it might be :
ISP------( Modem translate signal and get a public ip : 1.2.3.4 )--------Computer(get a private ip from modem, something like 10.x.x.x OR 192.168.x.x.x)

Now about dynamic/static addressing;
Static == never change
Dynamic == may change
Unless you are very lucky/pay a lot, you don't get static ip from your ISP, of course. And about your internal network (in case your modem acts like a router), the usual way for a router is to give computer dynamic ip using DHCP protocol (if you have nothing to configure to get on the network, you do use DHCP) but you could usually change it to use static ips (but you will need to get your hands dirty with some configurations).

Sorry about the confusion. I am new to this. Now I do understand my D-Link router, more or less, it assigns 192.168.x.xxx to each computer. That part I understood. I just wasn't sure if my modem did. I was going to set it up so the internet would go directly into one computer, then out the second ethernet card to my other computer. But I think I will stick with the D-Link Router I have.

Here is another question that goes along with this. On my D-Link internal web page I can configure the router. It is pretty straight forward. I noticed a word I never heard before except at McDonalds and Apple computers. What is a "MAC" address?

The router also gives me the option to assign one port, like port 80, to be used for public access. I am not sure if I need that if I have the 192.168.x.xxx that is assigned to each computer by the router. But if I did use it wouldn't I need different ports for ftp, http, smtp, pop3 etc?

The router I am using is a D-Link DI-524 router. I have been reading up on it and I understand a lot. I just want to make sure that I understand as much as I can about IP addresses and ports before I actually set up the server.

Thanks for the help.

Webwolf

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

just my ...

Thank You. This helps a lot. It is also answering some other questions I had but didn't ask yet. I guess my problem right now in part is that I don't just want to do something, I want to see the "bigger Picture." I am not sure if that makes any sense but I want to know the in and outs of what I am doing and seeing the connection and knowing why it is like it is, not just doing it and that is all. Since I am teaching myself all of this, it can get confusing at times(note my original post under this topic, LOL.) I am going to look up some info on ports now through wikipedia. I didn't realize the number of ports there are on a system. I thought maybe a few thousand but it appears there can be much, much more then that. Which leaves me with some security questions I will post in another thread later, once I research more on my own.

If anyone has any other info, it would be greatly appreciated. I just jumped into the middle of something that branches in every direction, then each branch branches off and on and on it goes, LOL. There is a lot to sort out but it is fun.


Webwolf

Well I now know what a port is, LOL.

Wikipedia:
"A port is a facility at the edge of an ocean, river, or lake for receiving ships and transferring cargo and persons to them."

Actually I see the connection. I was wondering something. Is there another name or technicle term for ports? Is port an abbreviation of a sort?

Webwolf

these links might help you understand cable modems:

http://computer.howstuffworks.com/cable-modem.htm

http://www.cable-modems.org/


this link might help you understand DSL modems:

http://computer.howstuffworks.com/dsl.htm


these links might help you understand IP ports:

http://www.interhack.net/pubs/fwfaq/...00000000000000

http://www.webopedia.com/quick_ref/portnumbers.asp

http://www.comptechdoc.org/independe...tsandaddr.html


this is the "official" IANA port list:

http://www.iana.org/assignments/port-numbers

Thank You. I have some reading to do

Webwolf

If I understand this correctly. Well let me post a paragraph from http://computer.howstuffworks.com/cable-modem7.htm first.


Inside the Cable Modem: MAC
The MAC sits between the upstream and downstream portions of the cable modem, and acts as the interface between the hardware and software portions of the various network protocols. All computer network devices have MACs, but in the case of a cable modem the tasks are more complex than those of a normal network interface card. For this reason, in most cases, some of the MAC functions will be assigned to a central processing unit (CPU) -- either the CPU in the cable modem or the CPU of the user's system.

Ok, if I understand this correctly. Then a MAC address would be needed with my D-Link router if the cable modem had to use the CPU on my computer opposed to the CPU in the cable modem itself? Hmmm, I have a lot more reading to do.

Webwolf