Re: EtherChannel mode ON ? Any catch?

I would also add that using LACP can be useful when end-to-end
connectivity is not reflected in the link status of the interface - for
example - using media converters or perhaps a QinQ service.

LACP control packets are sent at 30 second intervals after bundling and
give and end to end check. Using "lacp rate fast" this is reduced to 1
second (much more useful) Note that the dead time is 3x the hello
time... Unfortunately last time I looked I think only the high end
switches supported the fast timers :-(

Ivan

On 6/Oct/2010 11:37 p.m., Marko Milivojevic wrote:
> 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
>
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> :: 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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Received on Thu Oct 07 2010 - 11:10:30 ART