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.
> 
> 
> 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