Re: Mind Games - MST

Joe - just a change of interfaces from cat1-2 & cat3-4 on my setup....

topology

s1 =====23/24===== s2
 || ||
 || ||
 21/22 21/22
 || ||
 || ||
 s3=====23/24======s4

cat 1
spanning-tree mst 0 priority 4096
spanning-tree mst 1 priority 4096
spanning-tree mst 2 priority 4096
spanning-tree mst configuration
name CCIE
revision 10
instance 0 vlan 1-9,14-4094 (mapped by default)
instance 1 vlan 10, 12
instance 2 vlan 11,13

cats 2,3 & 4
spanning-tree mst 0 priority 32768
spanning-tree mst 1 priority 32768
spanning-tree mst 2 priority 32768
spanning-tree mst configuration
name CCIE
revision 10
instance 0 vlan 1-9,14-4094 (mapped by default)
instance 1 vlan 10, 12
instance 2 vlan 11,13

(bridge id on cat2 was root by default by the way)

cat 1 config

interface FastEthernet0/23
 switchport mode dynamic desirable
 spanning-tree mst 0,2 port-priority 240
 spanning-tree mst 1 port-priority 0

interface FastEthernet0/24
 switchport mode dynamic desirable
 spanning-tree mst 0,2 port-priority 240
 spanning-tree mst 1 port-priority 0

interface FastEthernet0/21
 switchport mode dynamic desirable
 spanning-tree mst 0-1 port-priority 240
 spanning-tree mst 2 port-priority 0

interface FastEthernet0/22
switchport mode dynamic desirable
 spanning-tree mst 0,2 port-priority 0
 spanning-tree mst 1 port-priority 240

cat 4 config

interface GigabitEthernet1/0/21
 switchport mode dynamic desirable
 spanning-tree mst 1 cost 1

interface GigabitEthernet1/0/22
 switchport mode dynamic desirable
 spanning-tree mst 1 cost 1

interface GigabitEthernet1/0/23
 switchport mode dynamic desirable
 spanning-tree mst 2 cost 1

interface GigabitEthernet1/0/24
 switchport mode dynamic desirable
 spanning-tree mst 0,2 cost 1

to summise
*cat2 mst 0, 1 & 2 root port is 0/23 (even by making port priority higher
for instances 0 & 2 on cat1 it see's a better cost 200000 on cat1 vs 400000
via cat 4)*
*cat3 mst 1 & 2 root port is 0/21 but 0/22 wins bid for mst instance 0 (due
to port-priority command set on cat1)*
*cat4 mst 1 root port is 0/21 | mst2 root port is 0/23 | mst0 root port is
0/24 (think iv met all the requirements for this switch)*

hmmm not 100% on this can anyone chime in

do we need the path into cat1 from cats2/3 to follow f0/21-22 for instance
2 & f0/23-24 for instance 1 & with the restrictions how would this be met?

Tony

On 16 October 2012 22:32, Tony Singh <mothafungla_at_gmail.com> wrote:

>
> think the confusion is in the question (agree)
>
> Use the port-priority command on 3560-1 to alter the path that traffic
> takes on switches 3560-2, 3560-3, *ok here because we have direct links
> use port priority on cat1*
>
> and 3560-4 using interface cost. *confusion is with the* "*and" keyword -
> because no direct link to cat1 from cat4 use cost to **manipulate*
>
> Ensure 3560-1 is the root switch for all instances. *use lowest priority
> on cat1 for instances 0,1 & 2*
>
> *will try to lab it mate, as this is an empty promise!*
>
>
> Tony
>
>
> On 16 October 2012 20:47, Tony Singh <mothafungla_at_gmail.com> wrote:
>
>> Agree
>>
>> --
>> BR
>>
>> Sent from my iPhone on 3
>>
>> On 16 Oct 2012, at 17:25, Mohammad Khalil <eng_mssk_at_hotmail.com> wrote:
>>
>> > You will create two instances 1 and 2
>> > The other will be in the default instance 0
>> >
>> >> Date: Tue, 16 Oct 2012 10:59:47 -0500
>> >> Subject: Mind Games - MST
>> >> From: marco207p_at_gmail.com
>> >> To: ccielab_at_groupstudy.com
>> >>
>> >> All,
>> >>
>> >>
>> >> I really hate questions like this, hence the reason I have problems
>> with
>> >> the CCIE lab.
>> >> Help me understand this supposedly easy question.
>> >>
>> >> s1 =====19/20===== s2
>> >> || ||
>> >> || ||
>> >> 21/22 21/22
>> >> || ||
>> >> || ||
>> >> s3=====19/20======s4
>> >>
>> >>
>> >> *Task 7.1*
>> >>
>> >> Due to large number of VLANS that exist within the current network, the
>> >> decision has been taken to migrate from 802.1 W spanning tree to 802.1S
>> >> across all switches. Configure 802.1S spanning tree configuration
>> with *3
>> >> instances* as follows:
>> >>
>> >> Region Name: CCIE
>> >> Revision: 10
>> >> *Instance 3* -- All other VLANs
>> >> Instance 1 -- VLAN 10 and 12
>> >> Instance 2 -- VLAN 11 and 13
>> >>
>> >> My Question ???? :
>> >> Do you create;
>> >> instance 1
>> >> instance 2
>> >> instance 3
>> >>
>> >>
>> >> *Task 7.2*
>> >> With 3560-1 as the core connected switch using 802.1S spanning-tree,
>> >> perform *traffic balancing* so that all traffic for VLANs contained in
>> >> Instance 1 is sent out of ports fa0/19 and fa0/20, Instance 2 is sent
>> out
>> >> of portFa0/21 and Fa0/22, and *Instance 0 must not be load balanced*.
>> >>
>> >> Use the port-priority command on 3560-1 to alter the path that traffic
>> >> takes on switches 3560-2, 3560-3, and 3560-4 using interface cost.
>> >> Ensure 3560-1 is the root switch for all instances.
>> >>
>> >> My Question ???? :
>> >> Based on Task 7.1, the first part of this task 7.2 would lead you into
>> >> only creating instance 2, & instance 1 and leaving instance 0 as the
>> >> All-other-VLANs? I would understand that if the put that CIST must be
>> >> compatible, this would require me to use instance 0 for all the other
>> >> VLANs, but this is not stated in the question so I'm again
>> overreading, not
>> >> reading enough or something.
>> >>
>> >> The second part of this task is confusing: What does this want you to
>> do.
>> >> "apply port-priority only on Sw1, and using Cost on SW2-SW3-SW4"
>> >>
>> >>
>> >>
>> >>
>> >> Sorry, but I really hate the type of language or lack thereof Cisco
>> uses on
>> >> the CCIE LAB.
>> >>
>> >> Thanks,
>> >> JS
>> >>
>> >>
>> >> Blogs and organic groups at http://www.ccie.net
>> >>
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Received on Wed Oct 17 2012 - 00:09:15 ART