RE: Couple of CCIE lab questions for experts

Hi Ivan,

1. The Customer's VLAN12 is different to the SP's VLAN12.
The incoming frame will be tagged with the standard dot1q header, i.e.
Customer VLAN12.
When it hits the switch port, QinQ will add another dot1q header in front of
the original dot1q header. Therefore it doesn't matter what is in the
customer's dot1q header because the SP switch never looks at it.

2. I'm not 100% sure about this one, but I think "no bridge <x> acquire"
command works on routers not switches. Can reconfig my lab tomorrow night to
test and confirm.

3. The likely issue is that you would've had a dynamic DLCI mapping on R2
somehow. If you can re-create the error message, do "show frame map" and you
should see a dynamic entry. This will also show you which interface has
picked up the dynamic mapping. If you clear the inarp cache and then retry
to add the static map, you should find that it works.

4. The correct way according to DocCD is to configure the session parameters
(e.g. IP addressing, auth, etc) under the multilink interface
http://www.cisco.com/en/US/docs/ios/dial/configuration/guide/dia_media-ind_m
ulti_ppp_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1055697

Kind regards,
Gavin

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Ivan
Hrvatska
Sent: 17 February 2010 11:08
To: Piotr Kaluzny
Cc: Cisco certification
Subject: Re: Couple of CCIE lab questions for experts

3. I can do configuration with main int in shut down state. After I
configure subinterfaces with frame interface-dlci command I unshut main int
and everything is fine. There is no IP add configured under main int. JUst
fr enc.
So, conclusion is that when you put enc frame (without IP add) on main
interface mapping of DLCI occurs after that? Because I don't put IP add
under main int, just enc frame.

1. Question was if you have provider's switch which has one access port for
customer who want QinQ, and that port is dot1q tunnel and it is access VLAN
12 (provider's VLAN). Customer also has VLAN 12 which is going to be
tunneled. Doesn't provider's VLAN 12 interference with customer's VLAN 12
which has to be tunneled?

On Wed, Feb 17, 2010 at 10:03 AM, Piotr Kaluzny <piotrk_at_ipexpert.com> wrote:
> Ivan,
>
> 1. Not sure if I fully understood the question but for QinQ in general
> one link should be configured as trunk and the other end as the tunnel
port.
> Routers configured with subinterfaces emulate the trunk end (packets
> are tagged across that link). Now when you configure it, you should
> assign a tunnel port to a VLAN ID that is dedicated to tunneling plus
> each customer requires a separate service-provider VLAN ID (metro tag).
>
> 3. I think that depending on IOS version it will not let you assign
> the DLCI already mapped via the main interface. It will be a good idea
> to configure main interface with frame-relay encapsulation and no IP
address.
> Then remove all subinterfaces configured, save the config and reload
> the router. After a reload you should be able to configure a p2p
> subinterface, assign it an IP address and move DLCI from the main
> interface to this p2p subinterface using "frame-relay interface-dlci"
command.
>
> Regards,
> --
> Piotr Kaluzny
> CCIE #25665 (Security), CCSP, CCNP
> Sr. Support Engineer - IPexpert, Inc.
> URL: http://www.IPexpert.com
>
>
> On Tue, Feb 16, 2010 at 7:21 PM, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:
>>
>> Hi,
>>
>> since I'm going through the prep for CCIE R&S I'm writing down some
>> questions to ask you guys:
>>
>> 1. QINQ - In scenario where you have R1 router connected on SW1 and
>> R2 router connected in SW2, and connection of switches goes like this
>> R1--SW1---SW3---SW4---SW2---R2. Task is to configure dot1q tunnel
>> (QinQ). Routers R1 and R2 have subinterfaces, one in VLAN 12 and the
>> other in VLAN 34. Routers are connected to appropriate switches to
>> access port in VLAN 12. After configuring that access port as dot1q
>> tunnel I have communication between R1 and R2 through both VLAN 12
>> and VLAN 34. My question is, how come that service provider's VLAN 12
>> (access port on SW1 and SW2) doesn't get in the way for customer VLAN
>> 12 (R1 and R2 are customer routers)?
>>
>> 2. FALLBACK BRIDGING - I have simple configuration for fallback
>> bridging of IPX traffic. As I understood, NO BRIDGE 1 ACQUIRE should
>> not forward packets to dynamically learned MAC addresses. On my 3560
>> that doesn't work. My traffic is still forwarded. Are there some
>> tricks or is just the bug?
>>
>> 3. FRAME RELAY MAPPING - simple scenario where I have R1 as hub and
>> R2, R3 as spokes. Task is to configure p2p links R1-R2 and R1-R3. As
>> I understood, inverse ARP will be activated when you put IP adress on
>> MAIN interface. As long as you are using subinterfaces there is no
>> need to put NO FRAME INVARP. So, I configured R1 with p2p subint and
>> IP add. I started configuring R2: configured ENC FRAM under main int,
>> made p2p subint and when I wanted to put FRAME INTERF-DLCI on my R2's
>> p2p subint msg says that my DLCI is already mapped to main interface?
>> Why?
>>
>> 4.PPP MULTILINK - you have 2 connections between two routers, FR
>> connections and you wanna configure multilink authentication. My
>> learning materials say that you have to configure ppp auth under
>> virtual template. I configured under multilink int and it works.
>> Question is: is the right way under virtual-temp or ppp auth can be
>> configured under multilink int?
>>
>> 5. RIPv2 over FR - simple scenario, one hub and two spokes. Hub has
>> multipoint subint and spokes have ip addresses under main interface.
>> All three routers have one loopback which is advertised via RIPv2. I
>> didn't put BROADCAST keyword in the mapping line just to see what
>> will happened. My spokes exchange routing updates, so one spoke knows
>> about other's loopback and vice verse.
>> Hub router doesn't get any update. What is the reason for that behavior?
>>
>> OK. I got number 5 question. My spokes learn about each other via
>> dynamic mapping which has BROADCAST feature on. :)
>>
>> That's it for now. Thanks.
>>
>> Regards
>>
>>
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>>
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Received on Thu Feb 18 2010 - 02:18:29 ART