Re: Connecting a user to AOL (anything I should know?!)

On 19 Feb, 12:18, Daniel James <wastebas...@xxxxxxxxxxxxxxxx> wrote:
In article
<news:39cc6b5e-c223-452f-870b-b669c1e09dc1@xxxxxxxxxxxxxxxxxxxxxxxxxxxx

, Jameshanle...@xxxxxxxxxxx wrote:
But you did it again. It is not a routing table!

It's a table, it's used for routing ... I agree that it's not used for
IP routing, so it's not an IP routing table,

I am saying that what is done with an ARP table is not called Routing.
That routing is not a general term that goes across layers. Or goes
across different types of protocol at a given layer.

It is a general term for Routing Protocols. IP , IPX. Not ARP.

(actually, correction, it may be a general term for RoutED protocols.
IP, IPX, e.t.c. Still though, Not ARP )

<snip>
Firstly.. I think when you spoke of "hard coded" MAC addresses, you
meant BIA - burned in address.

I think those are the same thing. "Hard coded" is a software engineer's
term and "burned in" is (or may be, I'm not qualified to judge) a
hardware engineer's term ... but they both basically mean that it can't
be changed.


I only said "burned in address" to translate what BIA stood for(the
term is probably just used in the ethernet specification). Hard
wired, in the firmware, yes.
I agree that maybe, burned in may have a general term used by
engineers. I have heard it used for CDs.. It is unambiguous in this
context, and probably all or most others.


I have not heard of a hard wired ARP table.. I doubt you meant that..
So, what would be the problem in updating an ARP table?

.. and "hard wired" is another term with the same meaning. Yes,
thanks.

The network engineer's term for MAC addresses in an ARP table that are
not intended to be changed is "static". I suppose a "static" entry in
an ARP cache isn't technically hard-coded, but I think it should be
clear what I meant.

static entries can be manually added or removed. As part of
configuring it. Software is there to assist in changing it.

Quite different to hard wired / the concept of MAC being hard wired.
Where they cannot be changed at all. It is in the circuitry. Maybe if
one is an electronic engineer / highly skilled with circuits, and got
physical with the circuitry and hacked it, it could be changed.


... some hardware needs to be reset to recognise a new MAC.

Maybe ... but that sounds like it's talking about bad equipment
mismanaging dynamic ARP entries rather than intentionally static ARP
entries.


ok.. I was just quoting the article, some of these places now where
you quote me, were part of me quoting the article. Not that that
created any misunderstanding, but just making that clear.

It brings up the question, of why then, "NAT Routers" ... contain an
option for MAC Cloning.

The forum article you linked to appears to be describing setup for a
cable router (at least, I see no specific mention of ADSL there).

yep

AIUI
cable routers do use ethernet protocols over cable, so the MAC will be
transmitted.

So Cable do and DSL doesn`t. interesting..

I am not familiar with WAN protocols as you are.. I am intrigued, what
background (books/type of work) gave you that knowledge?

I have heard of Routers stripping off Layer 2 from the packet it
receives, and replacing it with the Layer 2 used by the network it is
sending to.
But even if both would here use an Ethernet frame, as you may be
suggesting with Cable..Then do you still think the MAC will be the
same.. i.e. if

compA-->--->Cable modemA--->THROUGH THE HOUSES`S WALL!--->ISP`s
Router.

Wouldn`t "Cable modemA" change the MAC to that of the ISP`s Router?

I can see that -maybe- it would not have to. e.g. if a direct
connection, and (I guess if) the NI at the other end ignores MACs or
reads them but is in "promiscuous mode".


In the case of an ADSL router: If the router uses PPoE the MAC will be
visible on the WAN side. If a router supports PPoE then it will
probably allow it's WAN-side MAC to be configured, even though that
setting doesn't have any meaning for PPoA.


Interesting, I see PP=PPP with PPPoA/PPoA and PPPoE/PPoE
http://acronyms.thefreedictionary.com

<snip>
This used to be said of NTL's ethernet cable modems ... but I was under
the impression that it was a canard, and that the modem would just pick
up the first MAC that it saw after power-up ... seehttp://homepage.ntlworld.com/robin.d.h.walker/cmtips/swap.html


some interesting things on that link.


I find it hard to imagine that any ISP would distribute a cable modem
that would only talk to a single specific MAC address ... the support
overhead in getting that changed every time someone upgraded a PC or a
network card would be considerable.


regarding the support overhead. The user that did that would likely
not be completely clueless. And for the ISP it would be a standard
procedure, not something involving a time consuming diagnosis.


.

Relevant Pages

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