RE: Regarding bridge group and Bridge domain

I don't understand the idea of interworking and what it means yet..however,
look what I found. This guy has a small lab showing frame relay to vlan
(eth) AToM and I see the command "interworking ip" in there too.under the pw
class.

http://enotepad.wordpress.com/2010/04/14/framepvctovlan/

Aaron

From: CCIE KID [mailto:eliteccie_at_gmail.com]
Sent: Friday, January 13, 2012 1:16 AM
To: Aaron
Cc: Cisco certification
Subject: Re: Regarding bridge group and Bridge domain

hi aaron, thanks for the reply

Can u just give some brief about Atom Interworking. I m not very sure how it
works. can u give ur thoughts
one side of Ce to PE is ethernet and the other side is Frame Relay

On Wed, Jan 11, 2012 at 9:20 PM, Aaron <aaron1_at_gvtc.com> wrote:

I was told by someone a few months ago when I was config'ing my ASR9K's that
BG is a way of simply organizing the underlying BD's. I believe you can't
configure a BD without first config'ing an owning BG. So you can have
several BD's in one overarching BG. Again, the BD's are organized into a
BG. I guess you could create one to one....one bg for one bd....but I
didn't do my network that way....

I took common bd's and put them into one bg

The bd is what gets you the segregated broadcast domain/vlan entity that we
all understand. Not the bg. So the bd = broadcast domain. (funny that bd
doesn't stand for broadcast domain but instead stands for bridge domain, but
as I understand, the bd is in fact the broadcast domain....so the bg is a
way of organizing a bunch of bd's into one overarching bg.)

Yeah, so I don't think the owning BG allows any technical forwarding of
traffic or anything like that amongst underlying bd's.

As I understand it, you MUST enter the "l2vpn" config mode BEFORE you can
configure any bg/bd at all.

Also, as I understand it, AToM I think is cisco-speak for EoMPLS.....

And as I understand AToM/EoMPLS, this is known as MPLS L2VPN.... ethernet
frames over mpls frames over ethernet frames...don't you love it!

So stack looks like ... ip/eth/mpls/eth

Also, as I understand it, there are a variety of ways to accomplish MPLS
L2VPN/AToM.....i think EoMPLS is one of them....i think there is port mode
and vlan mode....i think there is VPLS (I believe for multipoint scenarios)
and I think EoMPLS might be more suited for p-to-p...not sure though, but
that's what I used in my network for something I'm doing....also, more
terminology...

I think in EoMPLS...

- the connection from edge/customer gear to the mpls imposition/disposition
device (label cloud edge device) is known as AC (attachment circuit)
--- so you should probably have (2) AC's, one on each edge of mpls cloud
that you are emulating layer 2 for...
- the mpls connection through the mpls cloud I believe is known as PW
(pseudowire)
- I think in some gear (ME3600) you provision the pw with command called
"xconnect" under perhaps the vlan svi or eth port (maybe that's where the
difference in port mode and vlan mode is for config'ing it)
- in IOS XR gear I see that it's not xconnect for the pw but is "neighbor
x.x.x.x" under the owning bd which is of course under the owning bg....
--- I think in both cases you specify encap mpls for xconnect/neighbor or a
pw class in which you specifiy in the pw class the encap mpls

Also in your link to ciscosupport I see that there is another type of maybe
it's mpls l2vpn, e-line (vpws).

From your other email, I don't know the difference from local connect and
local bridging...that link you sent shows local bridging using some dot1q
stuff on it and even qnq...maybe that's the difference. Not sure

This mpls l2vpn stuff btw is *very* different than MPLS L3VPN's....wayyyy
different. L3vpn is based on routing tricks with vrf instances and using
mp-ibgp as the signaling protocol in the mpls cloud to carry the uppermost
label for l3vpn segregation....(I think I heard someone say recently that
you don't really have to have an mpls core to do mpls l3vpn's, I was amazed)

Aaron

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of CCIE
KID
Sent: Tuesday, January 10, 2012 12:49 AM
To: Cisco certification; CCIE OSL
Subject: Regarding bridge group and Bridge domain

Hi fellas,

What is the exact difference between the bridge group and bridge domain in
L2VPN configs.

What is the exact purpose of bridge group and bridge domain in Atom configs

--
With Warmest Regards,
CCIE KID
CCIE#29992 (Security)
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