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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-- 
With Warmest Regards,
CCIE KID
CCIE#29992 (Security)
Blogs and organic groups at http://www.ccie.net