RE: Ether Channel Query!!

The bundled ports wont show up in the sh spantree command unless you
type in sh span int <physical port> which will show them in forwarding
state. As mentioned by Hammer as soon as you put the physical port into
an ether channel spanning tree process only shows the logical port in
the sh span tree.

See below e.g .. port 1/0/52 and 2/0/52 wont show up in the span tree
process but you can view their status by entering sh span <vlan> int gig
1/0/52 <detail> command,

#sh etherchannel summ

Group Port-channel Protocol Ports
------+-------------+-----------+---------------------------------------
--------
1 Po1(SU) LACP Gi1/0/52(P) Gi2/0/52(P)

#sh run int gig 1/0/52
Building configuration...

Current configuration : 181 bytes
!
interface GigabitEthernet1/0/52
switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 channel-group 1 mode active
end

#sh run int gig 2/0/52
Building configuration...

Current configuration : 181 bytes
!
interface GigabitEthernet2/0/52
switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 channel-group 1 mode active
end

#sh run int po1
Building configuration...

Current configuration : 144 bytes
!
interface Port-channel1
switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
end

#sh span vlan 2
VLAN0002
  Spanning tree enabled protocol rstp
  Root ID Priority 24578
             Address 0022.be9f.ab80
             This bridge is the root
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

  Bridge ID Priority 24578 (priority 24576 sys-id-ext 2)
             Address 0022.be9f.ab80
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
             Aging Time 300

Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- --------
--------------------------------
Po1 Desg FWD 3 128.616 P2p

#sh spanning-tree vlan 2 int gi2/0/52 de
 Port 616 (Port-channel1) of VLAN0002 is designated forwarding
   Port path cost 3, Port priority 128, Port Identifier 128.616.
   Designated root has priority 24578, address 0022.be9f.ab80
   Designated bridge has priority 24578, address 0022.be9f.ab80
   Designated port id is 128.616, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default
   BPDU: sent 25045070, received 73

#sh spanning-tree vlan 2 int gig1/0/52 de
 Port 616 (Port-channel1) of VLAN0002 is designated forwarding
   Port path cost 3, Port priority 128, Port Identifier 128.616.
   Designated root has priority 24578, address 0022.be9f.ab80
   Designated bridge has priority 24578, address 0022.be9f.ab80
   Designated port id is 128.616, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default
   BPDU: sent 25045075, received 73

#sh spanning-tree vlan 2 int po1 de
 Port 616 (Port-channel1) of VLAN0002 is designated forwarding
   Port path cost 3, Port priority 128, Port Identifier 128.616.
   Designated root has priority 24578, address 0022.be9f.ab80
   Designated bridge has priority 24578, address 0022.be9f.ab80
   Designated port id is 128.616, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default
   BPDU: sent 25045080, received 73

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
CCIE KID
Sent: 27 September 2010 15:29
To: --Hammer--
Cc: ccielab_at_groupstudy.com
Subject: Re: Ether Channel Query!!

Hey can u explain me the process and what r the packets exchanged so
that
how does STP come to know that that the particular port is bundled

What will be in the sh spanning-tree detail for that particular port
which
is been blocking
Whether it will be of forwarding state

That bundled link will be in which state in forwarding state in STP ah??
pls brief me about that??

On Mon, Sep 27, 2010 at 7:51 PM, --Hammer-- <bhmccie_at_gmail.com> wrote:

> CCIE KID,
> When you "bond" the two physical interfaces into a logical port
channel,
> you will pass traffic over both Fa0/1 and Fa0/2. STP treats the entire
> collection of physical interfaces as a single logical port. This is
all
> negotiated between the endpoints. Does that help?
>
> --Hammer--
>
>
>
> On 9/27/2010 9:17 AM, CCIE KID wrote:
>
>> I have a doubt in ether Channel
>>
>> This is my scenario
>>
>> SW1 fa0/1-------------------------------------------fa 0/1 SW2
>> fa0/2-------------------------------------------fa 0/2
>>
>> In STP SW1 is the root bridge and SW2 is the non root bridge , In SW2
fa
>> 0/1
>> is in forwarding state and fa 0/2 is in blocking state .
>> So in Ether channel, if we bundle fa0/1 and fa 0/2 ,traffic cannot be
>> passed
>> through fa 0/2 .
>> How Ether Channel informs STP about the bundling and makes the fa 0/2
into
>> forwarding
>> Can anyone explain me the process
>> I am expecting the experts to explain
>>
>>
>>
>> With Warmest Regards,
>>
>> CCIE KID
>> IN PURSUIT OF CCIE
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>>
Received on Mon Sep 27 2010 - 15:51:10 ART