Re: EtherChannel mode ON ? Any catch?

  I don't think Cisco officially pushes PAGP anymore. Most folks I talk
to at Cisco including Advanced Services and Segment One (I think SO is
changed names again) recommend LACP. Just FYI.....

And I hardcode everything I own. No negotiation if I own both sides.

--Hammer--

On 10/6/2010 8:36 AM, Shine Joseph wrote:
> I have been an advocate of ON due to the fact that we are not
> depending on any negotiation for setting up the ether-channel.
> When submitted a large enterprise network design to Cisco, they
> recommended to use PAgP when connecting two Cisco switches and use
> LACP when connecting from Cisco to third party switch.
> Some of the etherchannel requirements do not support all forms of
> negotiations; following are the couple that comes to my mind.
> WLCs do not support PACP for LAG - they need to be PAgP
> VSLs for VSSs do not support neither - they need to be ON
> PAgP is not supported on Cross Stack 3750 stack members - LACP is the
> only supported option
>
> So, the bets answer is IT DEPENDS when choosing the etherchannel mode.
>
> my 2 cents,
> -Shine
>
>
> --------------------------------------------------
> From: "Marko Milivojevic" <markom_at_ipexpert.com>
> Sent: Wednesday, October 06, 2010 6:37 PM
> To: "Tech Guy" <autechguy_at_gmail.com>
> Cc: "CCIE Lab" <ccielab_at_groupstudy.com>
> Subject: Re: EtherChannel mode ON ? Any catch?
>
>> With "on", you're running the risk of bridging loops if other end is
>> misconfigured. If that risk is acceptable and ~2s of initial
>> negotiation delay of LACP/PAgP isn't, use it.
>>
>> I would suggest you use LACP.
>>
>> --
>> Marko Milivojevic - CCIE #18427
>> Senior Technical Instructor - IPexpert
>>
>> Free CCIE Training: http://bit.ly/vLecture
>>
>> Mailto: markom_at_ipexpert.com
>> Telephone: +1.810.326.1444
>> Community: http://www.ipexpert.com/communities
>>
>> :: Sent from my phone. Apologies for errors and brevity. ::
>>
>> On Oct 5, 2010, at 19:35, Tech Guy <autechguy_at_gmail.com> wrote:
>>
>>> Hi GS,
>>>
>>>
>>> LACP takes some time to negotiate, while mode ON does not require it,
>>> and hence gives a better convergence time. I am not sure if there's
>>> any issue with using EtherChannel mode ON, instead of LACP (apart from
>>> user-misconfig issues). This is not clear in the DOC CD configuration
>>> guide.
>>>
>>> More specifically, if we have two Cisco switches, and need to
>>> configure ether-channel between them, would you recommend mode ON or
>>> LACP (open standard). E.g. issue with mode ON such as one link is
>>> recognised as UP at one end, but as DOWN by the switch at the other
>>> end.
>>>
>>>
>>> Appreciate your feedbacks.
>>>
>>>
>>>
>>> http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_44_se/configuration/guide/swethchl.html#wp1275503
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> Understanding EtherChannels
>>> These sections describe how EtherChannels work:
>>>
>>> EtherChannel Overview
>>>
>>> Port-Channel Interfaces
>>>
>>> Port Aggregation Protocol
>>>
>>> Link Aggregation Control Protocol
>>>
>>> EtherChannel On Mode
>>>
>>> Load Balancing and Forwarding Methods
>>>
>>> EtherChannel Overview
>>> An EtherChannel consists of individual Fast Ethernet or Gigabit
>>> Ethernet links bundled into a single logical link as shown in Figure
>>> 34-1.
>>>
>>> Figure 34-1 Typical EtherChannel Configuration
>>>
>>>
>>>
>>> The EtherChannel provides full-duplex bandwidth up to 800 Mb/s (Fast
>>> EtherChannel) or 8 Gb/s (Gigabit EtherChannel) between your switch and
>>> another switch or host.
>>>
>>> Each EtherChannel can consist of up to eight compatibly configured
>>> Ethernet ports. All ports in each EtherChannel must be configured as
>>> either Layer 2 or Layer 3 ports. The number of EtherChannels is
>>> limited to 48. For more information, see the "EtherChannel
>>> Configuration Guidelines" section. The EtherChannel Layer 3 ports are
>>> made up of routed ports. Routed ports are physical ports configured to
>>> be in Layer 3 mode by using the no switchport interface configuration
>>> command. For more information, see the Chapter 10, "Configuring
>>> Interface Characteristics."
>>>
>>> You can configure an EtherChannel in one of these modes: Port
>>> Aggregation Protocol (PAgP), Link Aggregation Control Protocol (LACP),
>>> or On. Configure both ends of the EtherChannel in the same mode:
>>>
>>> When you configure one end of an EtherChannel in either PAgP or LACP
>>> mode, the system negotiates with the other end of the channel to
>>> determine which ports should become active. Incompatible ports are
>>> suspended. Beginning with Cisco IOS Release 12.2(35)SE, instead of a
>>> suspended state, the local port is put into an independent state and
>>> continues to carry data traffic as would any other single link. The
>>> port configuration does not change, but the port does not participate
>>> in the EtherChannel.
>>>
>>> When you configure an EtherChannel in the on mode, no negotiations
>>> take place. The switch forces all compatible ports to become active in
>>> the EtherChannel. The other end of the channel (on the other switch)
>>> must also be configured in the on mode; otherwise, packet loss can
>>> occur.
>>>
>>> If a link within an EtherChannel fails, traffic previously carried
>>> over that failed link moves to the remaining links within the
>>> EtherChannel. If traps are enabled on the switch, a trap is sent for a
>>> failure that identifies the switch, the EtherChannel, and the failed
>>> link. Inbound broadcast and multicast packets on one link in an
>>> EtherChannel are blocked from returning on any other link of the
>>> EtherChannel.
>>>
>>>
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>>
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Received on Wed Oct 06 2010 - 08:43:47 ART