Re: EtherChannel mode ON ? Any catch?

Shine,

I totally agree with you, it depends what you are doing.

On Wed, Oct 6, 2010 at 6:46 AM, Ryan West <rwest_at_zyedge.com> wrote:

> I have to side with Marco on this as well. In a perfect world customers
> are not touching their cabling and randomly moving servers and what they
> thought were the cables associated with them. In reality cables can get
> swapped fairly easily.
>
> VSLs for VSS are mode on, but everywhere else I run LACP.
>
> -ryan
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Shine Joseph
> Sent: Wednesday, October 06, 2010 9:36 AM
> To: Marko Milivojevic; Tech Guy
> Cc: CCIE Lab
> Subject: Re: EtherChannel mode ON ? Any catch?
>
> 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/re
> >> lease/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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