Re: Load balancing

Im of a different opinion in that there is a distinct difference in
operation & definition but not in purpose between Sharing and Balancing.

By Definition:
- Load balancing is mechanism that helps make networks more efficient. It
distributes the processing of traffic *evenly* across a network with
multiple-paths, in order to get optimal resource utilization, maximize
throughput, and minimize response time.

- Load-Sharing is inherent to the forwarding process of a router to
*share*the forwarding of traffic if the routing table has multiple
paths to a
destination. If equal paths, traffic is shared based on the forwarding
process used. But if unequal, the traffic is distributed in inverse
proportion to the cost of the routes. That is paths with lower costs
(metrics) are assigned more traffic, and paths with higher costs are
assigned less traffic.

Although the terms are often used interchangeable, Load-Sharing is more
realistic and technically more correct, in that you can always share traffic
across multiple paths, even if in a unequal fashion. In simple terms, if you
were to look a two comparing traffic graphs, with load-balancing the two
graphs would be identical, but with load-sharing they might be similar but
the traffic flow pattern would be different.

Also if you look at the applications available to either, for load-balancing
you only have 2 options , where all other options will share traffic
inherently.

HTH
<ruhann>

On Tue, Jul 7, 2009 at 6:14 PM, jack daniels <jckdaniels12_at_gmail.com> wrote:

> Hi,
>
> So that means the only way to load share traffic is CEF ?
> Request you to fwd some links on how this load balancing happens and what
> all techiniques are available for load balancing.
>
> Reagrds
> J.Daniels
>
>
> On Tue, Jul 7, 2009 at 9:29 PM, Pavel Bykov <slidersv_at_gmail.com> wrote:
>
> > Pretty much.
> >
> > Control Plane:
> > 1. Routing protocol decides that routes are equal cost (including static)
> > and offers them to the routing table (up to preset limit. Default: 4,
> max:6)
> > 2. Routing table installs all offered routes up to preset limit
> >
> > Data Plane:
> > 1. CEF FIB is programmed from the routing table, resolves all adjacencies
> > (GLEAN entries for ARP) etc.
> > 2. Redundant entries are installed with sharing in mind
> >
> > Data plane forwards the packets, and it's CEFs task to load balance.
> > CEF cannot use flow mask in most cases, only source/destination pair and
> > optionally ID (sort of seed).
> >
> >
> http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_command_reference_chapter09186a0080417d88.html#wp1010171
> >
> >
> >
> >
> > On Tue, Jul 7, 2009 at 4:48 PM, jack daniels <jckdaniels12_at_gmail.com
> >wrote:
> >
> >> Hi,
> >>
> >> Please suggest -
> >> so routing protocol bring the two routes in routing table for processor
> to
> >> read and to load balance TRAFFIC we need CEF .... Cef will load balance
> >> traffic per flow and per destination.
> >>
> >>
> >> Regards
> >>
> >>
> >>
> >> On Tue, Jul 7, 2009 at 1:55 PM, Zaid Alwasity <zaidalwasity_at_hotmail.com
> >wrote:
> >>
> >>> Hi all,
> >>>
> >>> I think that load sharing means dividing the load manually between
> >>> multiple
> >>> device for example ,network 1-5 are served through router A ,and
> network
> >>> 6-10 are served through router B like HSRP though multiple stand-by
> >>> group,
> >>> and for load balancing both devices are actively serving the networks
> >>> 1-10
> >>> like GLBP.
> >>>
> >>> Regards,
> >>> Zaid
> >>>
> >>>
> >>> -----Original Message-----
> >>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf
> Of
> >>> Pavel Bykov
> >>> Sent: 07 July 2009 10:59
> >>> To: jack daniels
> >>> Cc: Cisco certification
> >>> Subject: Re: Load balancing
> >>>
> >>> for routining, equal cost routes are simultaneously installed in CEF.
> >>> CEF then load balances to what is predefined. Normally, it's SRC/DST
> pair
> >>> what makes the hash.
> >>> ip cef load-sharing
> >>> command changes the method of balancing.
> >>>
> >>> Software platforms (800/1800/2800/3800/7200) also enable you to load
> >>> balance
> >>> per packet in routnd robin fasion.
> >>> Then it's per interface command "ip load-sharing per-packet"
> >>>
> >>> Load sharing/balancing are similar terms which are not divided
> regarding
> >>> particular feature.
> >>> So you can refer to balancing as sharing and sharing to balancing.
> >>>
> >>>
> >>> On Tue, Jul 7, 2009 at 9:47 AM, jack daniels <jckdaniels12_at_gmail.com>
> >>> wrote:
> >>>
> >>> > Dear All,
> >>> >
> >>> > I'm very confused on the diffrent ways for load balancing the traffic
> >>> if I
> >>> > have more than one route in my routing table.
> >>> >
> >>> > Also please suggest diffrence between load sharing and load balancing
> >>> >
> >>> >
> >>> > Regards
> >>> > J.Daniels
> >>> >
> >>> >
> >>> > Blogs and organic groups at http://www.ccie.net
> >>> >
> >>> >
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> >>> >
> >>> >
> >>> >
> >>> >
> >>> >
> >>>
> >>>
> >>> --
> >>> Pavel Bykov
> >>> ----------------
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> >>>
> >>
> >
> >
> > --
> > Pavel Bykov
> > ----------------
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-- 
<ruhann>
Blogs and organic groups at http://www.ccie.net