Re: Do MAC addresses go to internet?

On Mon, 22 Oct 2007, in the Usenet newsgroup comp.os.linux.networking, in
article <471c048b$0$29252$ba620e4c@xxxxxxxxxxxxxx>, goarilla wrote:

Unruh wrote:

What is "cable"? IF you are one segment, one subnet of an ethernet,
all connected together on that ethernet with the same network AND
netmask, then all can see all. However, that is almost never the case
of an isp. The isp is insulated from your system by a modem and that
modem isolates your network.

huh all can see all ? what if you're on a switch ?

Well, we can "think" this problem out, or you could simple turn on a
packet sniffer and see what's on the wire. It may take some time,
but you will likely see a lot more MAC addresses than you thought.
The cable modem (or similar device) may be acting like a switch in
blocking monocast packets that are not for "your" IP address, but
they often pass _broadcast_ packets (such as DHCP stuff).

cable is like cable tv
one line in the ground were people with subscriptions and modems get
attached to
i think it's arranged in a bus like fashion but i'm not sure since i
have no real clue how it works.

As a simple explanation, you are correct.

disadvantage of cable is 1 global LIMIT per cable in which every
customer is limited by.
this means if a lot of people are downloading the max download speed
available to you can be only a fraction of the line's limit.

Yes, there are very few infinite width pipes in the world.

I'm asking this simply because although i have a decent understanding
of my own LAN network i would like to know more about bigger networks
like the ones ISP's administer.

Not knowing exactly what your LAN looks like, none the less it's
_probably_ something similar.

But tell us - do you monitor every packet on your LAN? Do you expect
your ISP to do so? Why? Noted else-thread, the ISP is worried about
the total number of packets on a segment. They planned the system based
on so many customers on each segment, up/down-loading so many packets.
That is a cost decision. Now someone _could_ draw attention to
themselves by hogging the bandwidth (up to the limit that their
router/modem allows), and perhaps the ISP administrator would look at
the traffic. They _might_ notice multiple usernames from a single
connection (as one crude example - there are others), so even if you
are masquerading everything through a single NIC, they might get an
indication of something funny.

Old guy
.

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