From: joshua lauer (jslauer@hotmail.com)
Date: Thu May 12 2005 - 20:45:40 GMT-3
That's the track I was taking....If Vlan's split up broadcast domains...how
do you get JUST broadcasts between them..I was thinking along the lines of
ip helper and such but I really dont have the equipment available to play
around with this...I am thinking about it though, kinda hard to think CCIE
when I'm in the airport :) I think the answer to the question isnt as
complicated as .1q tunnelling and such..It's probably more elemetary we all
just let it slide by our brains.
JL
JOSHUA LAUER
----- Original Message -----
From: "Dave Bregman" <DBregman@Houstons.com>
To: <ccielab@groupstudy.com>
Sent: Thursday, May 12, 2005 7:38 PM
Subject: RE: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>I think Josh is on the right track. It only has to do with broadcast
> traffic. Let's work backwards. Broadcast traffic is not normally
> forwarded between vlans. The only way it would be is if there were a
> bridge between the vlans. Therefore, it has to be some form of vlan
> bridging.
>
> While I think this is an excellent question, and I've been stewing about
> it for several hours. IMHO it's way beyond what I think you might see
> on the lab. YMMV.
>
> Dave Bregman
> CCIE #14626
>
>
>> -----Original Message-----
>> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
>> Behalf Of joshua lauer
>> Sent: Thursday, May 12, 2005 4:06 PM
>> To: Jongsoo kim; Brian McGahan
>> Cc: Group Study; ccie2be
>> Subject: Re: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>>
>>
>> Hey guys,
>>
>> I think I have a clue, it only mentioned broadcast traffic in the
>> question....not all traffic. I dont know the answer either, but I'll
>> hopefully find out shortly...It's a good one but I think I've
>> seen this type
>> of thing before I just cant remember where or why.
>>
>> josh
>>
>>
>> JOSHUA LAUER
>> ----- Original Message -----
>> From: "Jongsoo kim" <bstrt2002@gmail.com>
>> To: "Brian McGahan" <bmcgahan@internetworkexpert.com>
>> Cc: "Group Study" <ccielab@groupstudy.com>; "ccie2be"
>> <ccie2be@nyc.rr.com>
>> Sent: Thursday, May 12, 2005 7:01 PM
>> Subject: Re: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>>
>>
>> > Brian
>> > OK
>> > it is a tough one as Tim is struggling.
>> > If I summarize the requirement in my understanding,
>> > SW2 fowards a broadcast frame from vlan2 to the vlan 200
>> > SW1 forwards a broadcast frame from vlan 200 to vlan 2
>> > This basically rules out fallback-bridging option because
>> if bridges arer
>> > configured on SW1 and 2 between vlan 2 and 200, STP will do
>> its job by
>> > blocking one of two bridge and if I configue bridge on one
>> sw, then it
>> > wouldn't meet the requirement because both SWs need to
>> allow intervlan
>> > access.
>> > Hmm, I can't think of another method allowing intervlan
>> traffic. But I saw
>> > via some other email, using native vlan 802.1q trunk
>> between two SWs.
>> > I initaiily thought trunk may failed if native valn
>> mismatched but if
>> > trunk
>> > is manually configured, it may be ok.
>> > I also check CCO saying
>> > "Make sure the native VLAN for an 802.1Q trunk is the same
>> on both ends of
>> > the trunk link. If the native VLAN on one end of the trunk
>> is different
>> > from
>> > the native VLAN on the other end, spanning-tree loops might result"
>> >
>> http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/1222
>> 5se/3550scg/swv
>> > lan.htm#wp1200245
>> > So mismatching native vlan seems OK as long as there is no
>> potential SPT
>> > loop.
>> > Having said that, Maybe lets say F0/23 on SW1 and SW2 are
>> connected via
>> > 802.1q and assuming there is no vlan 200 in SW1 and no vlan
>> 2 in SW2.
>> > What about the below?
>> > SW2
>> > F0/23
>> > switchport mode trunk
>> > switchport trunk encapsulation dot1q
>> > switchport trunk native vlan 200
>> > SW1
>> > F0/23
>> > switchport mode trunk
>> > switchport trunk encapsulation dot1q
>> > switchport trunk native vlan 2
>> > In this way, SW2 will assume any untagged traffic received
>> via F0/23 as
>> > vlan 200
>> > and SW1 will assume any untagged traffic received via F0/23
>> as vlan 2.
>> > Let me know right or wrong for now as I am having fun with this :)
>> > Jongsoo
>> >
>> >
>> > On 5/12/05, Brian McGahan <bmcgahan@internetworkexpert.com> wrote:
>> >>
>> >> No BVI. Here is the task for the benefit of the group:
>> >>
>> >> 1.4. The port attached to R2 on SW1 is assigned to VLAN 2,
>> while the port
>> >> attached to BB2 on SW2 is assigned to VLAN 200. Configure
>> the network so
>> >> that when SW2 receives a broadcast frame originated in
>> VLAN 2 on SW1 it
>> >> is
>> >> forwarded to BB2, and when SW1 receives a broadcast frame
>> originated in
>> >> VLAN
>> >> 200 on SW2 it is forwarded to R2.
>> >>
>> >> 4 Points
>> >>
>> >>
>> >> Brian McGahan, CCIE #8593
>> >> bmcgahan@internetworkexpert.com
>> >>
>> >> Internetwork Expert, Inc.
>> >> http://www.InternetworkExpert.com
>> >> Toll Free: 877-224-8987 x 705
>> >> Outside US: 775-826-4344 x 705
>> >> 24/7 Support: http://forum.internetworkexpert.com
>> >> Live Chat: http://www.internetworkexpert.com/chat/
>> >>
>> >> ________________________________________
>> >> From: Jongsoo kim [mailto:bstrt2002@gmail.com]
>> >> Sent: Thursday, May 12, 2005 4:56 PM
>> >> To: Brian McGahan
>> >> Cc: ccie2be; Group Study
>> >> Subject: Re: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>> >>
>> >> Brian
>> >>
>> >> What about BVI interface in router?
>> >>
>> >>
>> >> On 5/12/05, Brian McGahan <bmcgahan@internetworkexpert.com> wrote:
>> >> Tim,
>> >>
>> >> Neither fallback bridging nor .1q tunneling are the solution ;)
>> >>
>> >> HTH,
>> >>
>> >> Brian McGahan, CCIE #8593
>> >> bmcgahan@internetworkexpert.com
>> >>
>> >> Internetwork Expert, Inc.
>> >> http://www.InternetworkExpert.com
>> >> Toll Free: 877-224-8987 x 705
>> >> Outside US: 775-826-4344 x 705
>> >> 24/7 Support: http://forum.internetworkexpert.com
>> >> Live Chat: http://www.internetworkexpert.com/chat/
>> >>
>> >> > -----Original Message-----
>> >> > From: nobody@groupstudy.com
>> [mailto:nobody@groupstudy.com ] On Behalf
>> >> Of
>> >> > ccie2be
>> >> > Sent: Thursday, May 12, 2005 4:00 PM
>> >> > To: 'Jongsoo kim'; Group Study; Brian McGahan; Brian Dennis
>> >> > Subject: RE: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>> >> >
>> >> > Hi Jongsoo,
>> >> >
>> >> > I tried your config but, alas, it didn't work.
>> >> >
>> >> > I also tried using that same config on both switches but
>> that didn't
>> >> work
>> >> > either.
>> >> >
>> >> > What bothers me most is that even if this did work, I
>> can't figure out
>> >> how
>> >> > it would.
>> >> >
>> >> > BTW, I didn't change anything on the rtr's on either side of the
>> >> Cat's.I
>> >> > left those interfaces with just the ip address configured.
>> >> >
>> >> > When you think about it, this I don't believe this should work.
>> >> Here's my
>> >> > thinking.
>> >> >
>> >> > Fallback bridging is for NON IP traffic ie non-routable traffic.
>> >> >
>> >> > But, for this scenario to work properly, I need to be
>> able to ping
>> >> from
>> >> > rtr-1 to rtr-2.
>> >> >
>> >> > Now, the Cat port connected to rtr-1 is configured to be
>> in vlan 2 and
>> >> the
>> >> > cat port connected to rtr-2 is in vlan 20.
>> >> >
>> >> > And, the cat's are trunked together via 802.1q
>> >> >
>> >> > With Fallback bridging configured, what happens to a
>> packet from rtr-1
>> >> > when
>> >> > Cat-1 gets it?
>> >> >
>> >> > Since it's an ip packet, I think the cat will process it
>> just like any
>> >> > normal ethernet frame ie it will see if the dest mac
>> addr is in the
>> >> mac
>> >> > table for vlan 2.
>> >> >
>> >> > Not finding it there, it will send it to all ports in
>> vlan 2 including
>> >> the
>> >> > trunk port connecting the 2 Cat's.When the 2nd Cat gets
>> it, I think
>> >> Cat-
>> >> > 2
>> >> > will drop it as it won't find that dest mac addr in it's
>> vlan 2 table
>> >> even
>> >> > though vlan 2 is bridged to vlan 20.
>> >> >
>> >> > What do you think?
>> >> >
>> >> > Tim
>> >> >
>> >> > _____
>> >> >
>> >> > From: Jongsoo kim [mailto:bstrt2002@gmail.com ]
>> >> > Sent: Thursday, May 12, 2005 3:53 PM
>> >> > To: ccie2be
>> >> > Subject: Re: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>> >> >
>> >> > I am doing fine.
>> >> >
>> >> > Can you just do something like the below on one of switch without
>> >> > configuring ip address?
>> >> >
>> >> > interface Vlan 2
>> >> > bridge-group 1
>> >> > interface Vlan 20
>> >> > bridge-group 1
>> >> > bridge 1 protocol vlan-bridge
>> >> >
>> >> >
>> >> > Jongsoo
>> >> >
>> >> > On 5/12/05, ccie2be <ccie2be@nyc.rr.com> wrote:
>> >> > Hey Jongsoo,
>> >> >
>> >> > It's good to hear from you.I hope you're doing well.As
>> for me, I'm
>> >> > working through the new IE practice labs as you can see.
>> >> >
>> >> > At the moment, I'm working on labs for which the
>> Solutions haven't as
>> >> yet
>> >> > been posted.
>> >> >
>> >> > I considered using Fallback Bridging to fulfill this
>> task but I can't
>> >> see
>> >> > how to use it as there are no L3 Cat ports involved in
>> this config.
>> >> >
>> >> > Fallback Bridging requires that L3 ports be put into a
>> bridge-group.
>> >> In
>> >> > this scenario, I could make the port connecting rtr-1 or
>> rtr-2 a L3
>> >> port
>> >> > but
>> >> > what about the trunk connecting the 2 Cat's?
>> >> >
>> >> > If you have any ideas, please show me what you would configure.
>> >> >
>> >> > Thanks, Tim
>> >> >
>> >> >
>> >> >
>> >> > _____
>> >> >
>> >> > From: Jongsoo kim [mailto: bstrt2002@gmail.com]
>> >> > Sent: Thursday, May 12, 2005 1:22 PM
>> >> > To: ccie2be
>> >> > Subject: Re: dot.1q tunneling - IE Vol II, lab 9, task 1.4
>> >> >
>> >> > How are you doing. Tim?
>> >> >
>> >> > if all you have to do is to make vlan 20 and 2
>> communicated in layer
>> >> 2,
>> >> > I think you need to configure Vlan-bridge in either CAT
>> 1 or CAT2 .
>> >> >
>> >> > Jongsoo
>> >> >
>> >> > On 5/12/05, ccie2be < ccie2be@nyc.rr.com
>> <mailto:ccie2be@nyc.rr.com> >
>> >> > wrote:
>> >> > Hi guys,
>> >> >
>> >> > I'm trying to figure out how to configure this.I think
>> dot.1q is the
>> >> way
>> >> > to go but I can't test this with the equipment I have.
>> >> >
>> >> > rtr-1------------- Cat-1---Cat-2----------------- rtr-2
>> >> > .2 < vlan 2>< vlan 20> .254
>> >> >
>> >> > | < 192.10.1.x/24 >|
>> >> >
>> >> > 802.1q trunks have been configured between the 2 3550's
>> and both Cat's
>> >> > have
>> >> > their system mtu set as 1504.
>> >> > I've configured each cat port connecting the rtr's as follows:
>> >> >
>> >> > Cat-1
>> >> > interface FastEthernet0/2
>> >> > switchport access vlan 2
>> >> > switchport mode dot1q-tunnel
>> >> > no ip address
>> >> > no cdp enable <- added by default
>> >> > spanning-tree bpdufilter enable<- added by default
>> >> >
>> >> > Cat-2
>> >> > interface FastEthernet0/24
>> >> > switchport access vlan 20
>> >> > switchport mode dot1q-tunnel
>> >> > no ip address
>> >> > no cdp enable
>> >> > spanning-tree bpdufilter enable
>> >> >
>> >> > With the rtr's I'm using I can't configure 802.1q trunking on the
>> >> ethernet
>> >> > ports connected to the Cat's.And, when I put the ip addr
>> on the phy
>> >> int,
>> >> > pings don't work from rtr-1 to rtr-2.
>> >> >
>> >> > Am I approaching this problem correctly?If I were able
>> to configure
>> >> the
>> >> > ethernet ports with 802.1q trunks, would this work?
>> >> >
>> >> > TIA, Tim
>> >> >
>> >> >
>> >>
>> ______________________________________________________________
>> _________
>> >> > Subscription information may be found at:
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>> >> >
>> >> >
>> >>
>> ______________________________________________________________
>> _________
>> >> > Subscription information may be found at:
>> >> > http://www.groupstudy.com/list/CCIELab.html
>> >>
>> >>
>> ______________________________________________________________
>> _________
>> >> Subscription information may be found at:
>> >> http://www.groupstudy.com/list/CCIELab.html
>> >
>> >
>> ______________________________________________________________
>> _________
>> > Subscription information may be found at:
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>>
>> ______________________________________________________________
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>
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