Re: Ether Channel Query!! from --Hammer-- on 2010-09-27 (Ccielab archives 09/2010)

This archive was generated : Fri Oct 01 2010 - 05:58:06 ART used to transmit traffic, such as Spanning Tree and unknown unicasts. The default port can of the command *show etherchannel summary* n/US/customer/tech/tk389/tk213/technologies_tech_note09186a0080094714.shtml">http://www.cisco.com/en/US/customer/tech/tk389/tk213/technologies_tech_note09186a0080094714.shtml 2900/2950/3550 section so take it for what it is AM, HEMANTH RAJ wrote: yeah Hammer u right ,But my question is how that LACP/PagP protocols handle and sends the traffic to the destination without any formation In reality if there are two ports which is forwarding and there will be a formation of loop,MAC table instability which results in a broadcast storm how does it is not happening? On Mon, Sep 27, 2010 at 10:12 PM, --Hammer-- <bhmccie_at_gmail.com <mailto:bhmccie_at_gmail.com>> wrote: That's the trick. Both ports are NOT forwarding. The port-channel IS. The port-channel is what STP monitors and places in a forwarding state. It is unaware of the individual ports. On the other side of the cables, the receiving switch is receiving STP on the port-channel. Not on an individual port associated with it. So the STP merely hands instructions to the port-channel interface to send out BPDUs. It doesn't care how they get there. The Port-channel interface (and associated PAGP/LACP protocol) are responsible for getting the BPDU across the wire. STP does not see both ports in a forwarding state. --Hammer-- On 9/27/2010 11:36 AM, HEMANTH RAJ wrote: hey Hameer i m asking about loop avoiding mechanism .If both the ports are forwarding and STP is not aware of the both the ports,then thee will be a chance of loop forming on that particular channel On Mon, Sep 27, 2010 at 10:01 PM, --Hammer-- <bhmccie_at_gmail.com <mailto:bhmccie_at_gmail.com>> wrote: 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 _______________________________________________________________________ Subscription information may be found at: http://www.groupstudy.com/list/CCIELab.html Blogs and organic groups at http://www.ccie.net _______________________________________________________________________ Subscription information may be found at: http://www.groupstudy.com/list/CCIELab.html Blogs and organic groups at http://www.ccie.net _______________________________________________________________________ Subscription information may be found at: http://www.groupstudy.com/list/CCIELab.html -- 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 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 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 at http://www.ccie.net on Mon Sep 27 2010 - 12:09:29 ART title="Related messages"> [ Message body ]

Paul Cocker: "Re: Ether Channel Query!!"

CCIE KID: "Ether Channel Query!!"

Paul Cocker: "Re: Ether Channel Query!!"

Contemporary messages sorted

by messages with attachments

hypermail 2.2.0