Re: DNS replication on 2 domain on 2 forests

"Ace Fekay [MVP]" <PleaseAskMe@xxxxxxxxxxxxxx> wrote in message
news:O8zQ1OmHHHA.1248@xxxxxxxxxxxxxxxxxxxxxxx
In news:_bAfh.5254$GB1.2936@xxxxxxxxxxxxxxxxxxxx,
Herb Martin <news@xxxxxxxxxxxxxx> stated, which I commented on below:

but I do want to point out that it is actually controlling the
traffic by directing it between the ports in question based on
source and destination MAC switch ports.

Then that is bridging -- or level 2 -- decision making.

Routers work at the network protocol (level 3) level to
make their decisions. (And they join multiple "broadcast
domains.")

As I pointed out in one of my earlier posts.

Good. Then you were correct when you said that part.


Bridging alone implies it is connecting only two segments,

No, bridging is a connection between multiple "collision
domains" (which we casually refer to as segments).

There is NO implication of "only two" segments in bridges;
single bridges have historically connected many segments.

Or broadcasts domains, as Intel documents call it.

No, that is what ROUTERS do as you said above (when you
were correct) and indicate you said in previous posts.

You are continuing to confuse the features and functions of
Routers and Bridges.

Bridges EXTEND the broadcast domain by uniting what
would otherwise be multiple broadcast domains.

Maybe the word "joining" (which we are both using but
doing to imprecisely) is confusing you.

Let's try it a little more explicitly and see if that helps you:

Routers router traffic between multiple broadcast domains.

Bridges move traffic and extend the broadcast domain
between different collision domains (that would be different
broadcast domains without the bridge to help -- but with
the bridge are NOW all a single broadcast domain.)

When one uses the term "bridge", it is often referred to connecting two
segments. When one uses the term "switch", it refers to a multi-port
bridge (a switch) to connect multiple segments.

Such imprecision is useless for learning or troubleshooting.

Both bridges or switches (even routers or router switches)
can move traffic between different segments*, either two, or
many. The difference is NOT "how many" segments, nor
the fact that the device assists in moving traffic, the difference
is in HOW and WHAT gets moved.

*Segment is another slippery word that tends to be used
imprecisely (by all of us for convenience) but much be
clearly defined when NOT absolutely clear by context OR
when dealing with anyone who hasn't got a clear understanding
of these distinctions -- IF we wish to be helpful and not just
confuse the issue even more.

Segments can be a physical "lengths of wire", separate from
all others not continous.

Segments can be a physical "lengths of wire", joined by
connectors but separate from all others not continous or
joined by electrical devices.

Segments can be a physical "lengths of wire", joined by a
repeater into a single COLLISION domain, but separate
from all other collision domains (one leg or side of a Bridge
perhaps.)

Segments can be a physical "lengths of wire", joined by a
possible repeaters, but isolated from all other segments by
routers which isolate the segment into a single broadcast
domain.

So:
Segments can be a physical "lengths of wire" on one side
of a switch, hub, repeater, bridge or other device where the
really interesting issue is what the device does with the
traffic on that segment or with other segments.

where a switch has mutliple segments, therefore it is essentially a
multi-port bridge, so, yes it does bridging functions, but on
multiple ports. T

Your main problem here seems to be that you really
misunderstand the KEY points of bridging and routing
and how they differ -- arguing from ignorance is not
going to make your initial mistakes go away. Only learning
the difference and how to explain it to those who come
looking to you for help will do that.

therefore it 'switches' traffic between the appropriate ports based
on source and destination MACs.

Again, SOME switches use ROUTING mechanisms to make
such switching decisions -- others use bridging mechanisms
to make these decisions when switching between two OR
MORE collision domains.

If you will just FIRST learn the differences (and similarities)
between bridging and routing you will be much better prepared
to both understand what switching really is -- and is not -- and
to explain all of this to those who seek your help.

You cannot "make yourself right" by continuing to try to explain
away your basic mistakes -- only by adopting both the correct
terminology and keying in on the key concepts will your
overcome these problem, learn, and best help others.

BTW: The MOST important difference for network admins
is that: Bridges propagate broadcasts, while Routers block*
broadcasts.

* Technically, routers don't "block" broadcasts, they just
ignore them, but the best mental picture is to treat routers
as BARRIERS to the propagation of broadcasts. This is
both a good (isolation) and a bad (steps must be taken when
broadcasts traffic or results are important) feature.

Herb, to end this discussion, I jsut want to say what I've learned about
bridging and switching over the past 20 years or so I've read in tech
books and various articles, such as those that I previously posted, that
point out exactly what I said.

It doesn't matter how long you took to learn it if you learned
it wrong -- arguing from ignorance will still not be helpful
to YOU or to those you wish to help.

I'm tired of arguing...

Then either get it right or stop arguing. Continuing to argue
on your part when you have had it explained carefully and
fully to you is just foolish.

Just admit (to yourself -- you don't need to tell me) that you
have something to learn here and JUST LEARN IT.

I will help if you continue to post -- time permitting -- but
I will not do you the disservice of treating you as if you are
too dumb (or even to stubborn) to learn this.

I know you well enough to know that you are both capable of
learning this correctly (no matter how badly someone of some
book has confused you in your past experience) AND that
once you learn it you will help others to do so.

You are definitely worth the effort; you are NOT some Internet
troll who argues just so you can see your message in print and
so I must presume you wish to actually learn this if you continue
to post either questions or incorrect information.

It would be better however, if you dispensed with the mistakes
and just asked questions until you get it right.....


--
Herb Martin, MCSE, MVP
Accelerated MCSE
http://www.LearnQuick.Com
[phone number on web site]





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