Re: Personal Data and Security

On Fri, 21 Aug 2009 22:11:22 -0400, Nick Naym wrote
(in article <C6B4CC0A.43DC5%nicknaym@[remove_this].gmail.com>):

In article jollyroger-5DDBDE.20390621082009@xxxxxxxxxxxxxxxxxxx, Jolly Roger
at jollyroger@xxxxxxxxx wrote on 8/21/09 9:39 PM:

In article <C6B4B38F.43D9B%nicknaym@[remove_this].gmail.com>,
Nick Naym <nicknaym@[remove_this].gmail.com> wrote:

In article jollyroger-14C0DF.15583321082009@xxxxxxxxxxxxxxxxxxx, Jolly
Roger
at jollyroger@xxxxxxxxx wrote on 8/21/09 4:58 PM:

In article <C6B4664F.43D6B%nicknaym@[remove_this].gmail.com>,
Nick Naym <nicknaym@[remove_this].gmail.com> wrote:

I went to Netgear's site to change the
security from WEP to WPA

Stop saying this. It's not true. What you actually did was log into your
router's configuration web page.

Are you saying that every Netgear router has it's own, individual web page
located at the Netgear site?

No. Your router is simply resolving the domain name to the router's
internal IP address. Your web browser is not going out to the internet
at all.

The fact that all Netgear routers have the same 192.168.1.1 address
therefore has nothing to do with each one's actual online identity?

Not a thing. Some IP address ranges are 'private' ranges and are not routed
over the Internet. These include:

10.x.x.y, where 'x' is a number from 0 to 255 and 'y' is a number from 1 to
254

172.16.x.y through 172.31.x.y

192.168.x.y

169.254.x.y

127.x.x.y is a special case.

The 10.x.x.y range is a Class A Private Network, because Class A addresses
run from 1.x.x.y to 126.x.x.y. (Well, to 127, but as I said 127 is a special
case.) The 172.16 through 172.31 ranges are Class B Private Networks; Class B
runs from 128 to 191. The 192.168 range is a Class C Private Network; Class C
runs from 192 to 223. There are Class D and Class E networks, but no-one uses
them on the Internet so they don't count. Class A networks can have up to
16,777,214 IP addresses assigned; a Class A private net, as dealt out by most
Apple AirPort Extreme routers, could in theory have 16.8 million users. In
fact the router would melt a long time before that happened. A Class B
private net could have 65,534 IPs. A Class C could have 254 IPs.

A private net is just that: a network that is not directly associated to
other nets. Your home net is a private net, you can have any number (up to
the limit of IPs allowed) of users on your own net. Your net is linked to the
Internet by your router, which talks between two networks: yours and the
Internet. Your router has _two_ IP addresses: one on your private net, and
one on the Internet. It acts as a gateway between your net and the outside
world. The IP it has on the Internet is assigned to it by your ISP out of its
pool of Internet-routable IPs. The IP it has on your net is self-assigned.
Typically for a Netgear this is 192.168.0.1 or 192.168.1.1, but you can set
your router's internal IP to be anything you want. It's a bad idea to use
anything except a private net IP , 'cause if you use a public net IP you
might use _someone else's_, bought and paid for, IP, and they'll be pissed
when that happens 'cause only one person can have an IP on any one network.
They will find out who liberated their bought and paid for IP and they will
take action to get it back. It's also a bad idea to use an IP in the 127
range 'cause that's a special case, and a bad idea to use a 169.254 address
'cause that's another special case. My AirPort Extreme came set to a 10
address range, and I changed it to a Class C range 'cause, well, I could and
I didn't feel like playing with a 16.8 million IP address space. I could have
cut it down below even the 254 IP address space of a Class C, but that would
have been too much like work. It's usually best to stick the router IP either
at the very bottom of the range (192.168.x.1) or at the very top
(192.168.254) to avoid certain technical problems; most network addressing
tools work better if you stick the router at the bottom of the range.

Pretty much all modern home routers ship with two technologies turned on:
NAT, Network Address Translation, and DHCP, Dynamic Host Configuration
Protocol. NAT is what allows the router to sit between your private net and
the Internet: it gets a message from computer #11 at 192.168.55.99 asking
permission to talk to Yahoo (at 69.147.76.15 out on the Internet) and makes a
note of it, then connects to Yahoo... and when it gets a reply, passes the
reply to computer #11. Yahoo sees a connection not to computer #11, but to
the Internet IP that your router has. Computer #11 doesn't see your router,
it sees Yahoo. That's why putting even 254 units on one home router will kill
the router, it can't handle that many requests for NAT. (A _business_ router
can handle hundreds, even thousands, of requests, though. That's why home
routers can cost as little as $20 but business routers cost thousands.)

You might want to look at <http://www.howstuffworks.com/nat.htm>.

DHCP allocates IPs on networks, including most home nets. If you have a Class
C network, you can have up to 254 IPs. Running around setting fixed IPs for
254 devices will get old really quickly; it's much worse with a Class B
network, and 65534 IPs, and effectively impossible with the 16.8 million IPs
of a Class A net. With DHCP, you don't have to. The DHCP server (in this
case, your router) will automatically hand out an IP to anything on the net
which asks for it... up to the number of IPs available. Each device on the
net has to have its very own, unique, IP. No sharing. Typically the 'DHCP
pool' of available IPs is less than the total IPs that can be on that net,
because some have to be reserved. The router itself must have one, for
example, and can't share that one. Usually servers and printers and such
devices have fixed IPs, too. Most home routers come ready to share out IPs
from a limited pool, such as the IPs starting at 192.168.99.100. That gives
the admin 100 IPs he can use for fixed IPs, while allowing 154 IPs for DHCP.
That's called 'excluding' IPs from the DHCP pool. It's one of the things that
can be changed using most router's configuration pages; if you know you will
never need more than 25 fixed IPs, you can start your DHCP pool at
192.168.32.26. Good routers, such as Apple's AirPorts, can also do
'reservations': you can tell the router that if a certain device, identified
by its MAC hardware address, which is unique in the world, shows up, the
router is to give it a certain IP address, every time. That IP is in the pool
but is not given out unless that particular device shows up. On my home net,
for example, I have fixed IPs for my server, my printers, and my main
computer, and reserved IPs for my laptop and certain other machines.



--
email to oshea dot j dot j at gmail dot com.

.

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