Re: Ether Channel Query!!

  Someone step in if I mis-quote something.

You're statement is a bit off. STP is not forwarding on both ports. STP
is forwarding on the port-channel. STP is no longer aware of the
individual ports. How the channel handles STP traffic is a different
matter. I don't think STP sends traffic on both ports in a LACP or PAGP
channel. I think the L2 protos (STP, CDP, DTP, etc) are just passed on
the primary link. I'm not where I can google this to confirm it. Anyone?

--Hammer--

On 9/27/2010 11:25 AM, HEMANTH RAJ wrote:
> Hey If STP has forwarding both ports, then there will be chance of
> loop formation
> wat is the actual mechanism
> how does it prevent loops at the same time it makes all the ports
> forwarding
>
> can anyone explain me?
>
>
> On Mon, Sep 27, 2010 at 8:39 PM, --Hammer-- <bhmccie_at_gmail.com
> <mailto:bhmccie_at_gmail.com>> wrote:
>
> Thanks Saulat for the quick lab up....
>
> --Hammer--
>
>
>
> On 9/27/2010 9:51 AM, Saulat Ali wrote:
>
> 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>
> [mailto: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 <mailto: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
> <mailto: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
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>
> --
> Problems arise Bcoz we talk,prblms r not solve bcoz we dont talk So
> gud r bad talk to ur affectionate one's freely
>
> Urs Friendly,
> HP HEMANTH RAJ

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Received on Mon Sep 27 2010 - 11:31:53 ART