From: Simon Baxter (Simon.Baxter@xxxxxxxxxxxxxx)
Date: Tue Aug 15 2000 - 19:59:00 GMT-3
Hey, you can never know it all - just know enough to do your job well (and
pass the ccie obviously!! (which you do!!))
I should have let it go, but after the don't-know-how-many 14 hour straight
study days - I was a little crazy last night!!
Simon
-----Original Message-----
From: Earl Aboytes [mailto:earl@linkline.com]
Sent: Tuesday, August 15, 2000 10:37 PM
To: Simon Baxter; Forest Riek
Cc: Matt Lachberg 3; ccielab@groupstudy.com
Subject: RE: bridge question
I was wrong with my original response, as other people have pointed out. I
was under the misconception that to route and bridge over the same interface
you had to have IRB or CRB enabled and thus dlsw was performing a function
like IRB. This is not true. I did a little more digging and found the
following information.
Cisco Bridging software:
Provides concurrent routing and bridging, which is the ability to bridge a
given protocol on some interfaces in a
router and concurrently route that protocol on other interfaces in the same
router.
Provides integrated routing and bridging, which is the ability to route a
given protocol between routed interfaces and
bridge groups, or to route a given protocol between bridge groups.
Below is the router output that lead me to my original answer. Notice how
you are bridging and routing on the same interface. If you want to move any
protocol from bridged to routed or vice versa, you must enable crb or irb.
r4#sh int irb
Ethernet0
Routed protocols on Ethernet0:
ip ipx
Bridged protocols on Ethernet0:
appletalk clns decnet vines
apollo xns
Software MAC address filter on Ethernet0
Hash Len Address Matches Act Type
0x00: 0 ffff.ffff.ffff 1766 RCV Physical broadcast
0x2A: 0 0900.2b01.0001 0 RCV DEC spanning tree
0xC0: 0 0100.0ccc.cccc 2616 RCV CDP
0xC2: 0 0180.c200.0000 0 RCV IEEE spanning tree
0xD8: 0 00d0.58ad.4a80 1764 RCV Interface MAC address
Loopback0
Routed protocols on Loopback0:
ip ipx
Serial0
Routed protocols on Serial0:
ip ipx
Man! Just when you think you know this stuff........
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Earl Aboytes CCIE #6097
Senior Technical Consultant
GTE Managed Solutions
805-381-8817
earl.aboytes@verizon.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of Simon
Baxter
Sent: Tuesday, August 15, 2000 2:02 AM
To: Forest Riek
Cc: Earl Aboytes; Matt Lachberg 3; ccielab@groupstudy.com
Subject: RE: bridge question
DLSW+ still doesn't do as Earl said : "When you turn on dlsw it enables
irb".
It's a bridging protocol. It works in conjunction with routing. It may do
one thing or another with a non-routED protocol, but it's primary function
is bridging.
It has no direct correlation to IRB.
Simon
-----Original Message-----
From: Forest Riek [mailto:forestr@gte.net]
Sent: Tuesday, August 15, 2000 6:36 PM
To: Simon Baxter
Cc: Earl Aboytes; Matt Lachberg 3; ccielab@groupstudy.com
Subject: Re: bridge question
DLSW+ will 'bridge' any protocol on a LAN interface that routing is not
currently enabled on. When you enable DLSW+ in a router, you are creating a
virtual interface that you use to bridge to. Then DLSW+ will encapsulate
the
traffic and forward it across the network to the designated peer.
For example, ethernet interface with IP address. You also have IPX on the
ethernet segment, but the router is not configured for IPX. The router will
route the IP traffic and DLSW+ will 'bridge' the IPX to the peer router. (I
know, it happened to me.)
You can filter the DLSW+ traffic to prevent the IPX from being 'bridged',
but a
quick and dirty solution is to enable IPX routing just on the ethernet
interface.
I hope this helps.
Forest Riek
Data Sales Engineer (CCIE in training)
Verizon Enterprise Solutions
Simon Baxter wrote:
> Since when??
>
> IRB and DLSW operate independently. You can have DLSW + irb or DLSW + crb
> or DLSW on it's own....
>
> Like I said, DLSW is a nice way to bridge non-routable protocols - why
would
> it automatically IRB or CRB??? There's no 'R' !!
>
> -----Original Message-----
> From: Earl Aboytes [mailto:earl@linkline.com]
> Sent: Tuesday, August 15, 2000 5:06 PM
> To: Matt Lachberg 3; ccielab@groupstudy.com
> Subject: RE: bridge question
>
> When you turn on dlsw it enables irb.
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Earl Aboytes CCIE #6097
> Senior Technical Conultant
> GTE Managed Solutions
> 805-381-8817
> earl.aboytes@verizon.com
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Matt
> Lachberg 3
> Sent: Monday, August 14, 2000 11:19 AM
> To: ccielab@groupstudy.com
> Subject: FW: bridge question
>
> Theoretically, why don't you need to enable crb with dlsw+. Or does the
> enabling dlsw+ somehow create the bridging / routing capability in the
> router?
> Matthew Lachberg, CCNP, CCDP, MSCE
> -----Original Message-----
> From: Simon Baxter [mailto:Simon.Baxter@au.logical.com]
> Sent: Monday, August 14, 2000 11:02 PM
> To: Cisco@datastreet.com; ccielab@groupstudy.com
> Subject: RE: bridge question
>
> It will enable the ieee spanning tree protocol and enable bridging on the
> ethernet. If you're routing IP somewhere else on the box you'll need to
run
> concurrent routing and bridging and define ip as a bridged protocol. This
> will be the same for any other routable protocols (protocols with a layer
3
> structure).
> In the most basic sense, yes, your config will enable bridging.
> -----Original Message-----
> From: Cisco@datastreet.com [mailto:Cisco@datastreet.com]
> Sent: Tuesday, August 15, 2000 2:36 AM
> To: ccielab@groupstudy.com
> Subject: bridge question
>
> Will this configuration bridge on Ethernet 0 or must I add "no ip routing"
> globally in order to enable bridging?
> interface ethernet 0
> no ip address
> bridge-group 1
> !
> bridge-group 1 protocol ieee
> Matthew Lachberg, CCNP, CCDP, MSCE
>
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