Hi all...I connect to the internet with RoadRunner Cable and using the modem they gave me...my question is if someone is attacking my machine and I shutoff the modem and disconnect the computer but later on I decide to connect another computer that I have to the modem...when I go online I will have the same IP as before even thought its a different computer? Whoever was targeting my computer before will still think this other computer is the first? What can I do have different IPs with the 2 computers(without having to pay for a second IP but will consider if no other way) Using a router or whatever its called...this I know will let me have both computers connected at the same time but will it separate one from the other (I mean as if I had 2 different IPs?) Thanks in advance and sorry not computer expert

Using a router or whatever its called...this I know will let me have both computers connected at the same time but will it separate one from the other (I mean as if I had 2 different IPs?) If you buy a router with 4 LAN (local area network) ports you can then connect both PC's. Setup properly, this will put both PC's in a network and they will not only be able to connect to the internet, they'll also be able to communicate with each other and share files. Yes, they will have different IP's, this is normal and necessary since you can't have two devices on the same network segment that have the same IP. However, both IP's would end up in the same subnet, allowing them to communicate and share. Those are internal IP's however. Your router would have the external (public) IP address. As to changing your IP, if you change computers it could change. That depends on your provider. Most have the IP connected to the MAC address of the unit connected to the modem. In a lot (not all cases) if the MAC changes (ie: the equipment changes) then so will the IP. No guarantee's though, to find out for sure if this is the case with your ISP, you'd have to call and talk to their support people.

When your PC connects to the server via the cable modem it's assigned an IP Address. Depending on how the server is configured it will either give you the same IP Address over and over (static addressing), or the first available address from a pool of IP Addresses (dynamic addressing). Your TCP/IP software periodically renews the connection so it's possible if you have a dynamic IP Address to be assigned a new one ever few hours or days. Typically though you get the same one. If it does change it's almost always only a digit or two off in the last octal (190.140.12.3 goes to 190.140.12.17, fer example). If you create a local LAN off a router or host PC it's exactly the same as off a router: Your "gateway" IP Address is what we're talking about here. Your internal, LAN addresses are never seen outside the LAN and the local server/router keeps track of traffic to and from the Internet gateway by connection. To attack your machine they have to be able to "see" the machine's memory address ports and that's what your firewall is for. Routers automatically drop all incoming packets that aren't responses to outgoing packets and a software firewall like Windows Fireall or Norton does the same thing, though not quite as efficiently. The only effective attack against a firewalled LAN or PC is a Denial of Service attack, where the attacker floods your gateway with so many packets that it slows or stops legitimate network traffic. The hacker can't take over your PC, he just makes sure you can't use the Internet. A DOS attack isn't so easy to execute. He's actually attacking your provider and they have lots of bandwidth and tracking software to detect and block DOS attacks these days. A Distributed DOS (DDOS) attack, where the attacker uses hundreds or thousands of slaved PCs to execute the attack, is harder to defend against but ISPs have gotten pretty good at dealing with those, too. Some people are paranoid enough to use IP morphing software so from moment to moment they switch between a large bank of external forwarding servers called "anonymizers". Each anonymizer reports its own IP Address instead of yours to outside observers. Because he never knows which server you'll be connecting through at any given time it's just about impossible to attack your gateway. However this is a lot of trouble, slows your throughput, and almost never worth the bother.

The best way is to learn on how to protect your network and computer as good as possible, so that can minimize the security risks.