From: sabrina pittarel (sabri_esame@yahoo.com)
Date: Thu May 10 2007 - 14:36:48 ART
2.
>
> SW1 - dst-mac
> SW2 - src-mac
>
is what I would do. Remember that L2 learning happens
on the etherchannel regarless of the physical link the
frame is coming in thru, so it is totally irrelevant
whether a bidirectional flow enters thru a port
channel member and exits from another.
src-dst-mac or src-dst-ip I think were implemented to
improve the distibution across the several
etherchannel links in a many to many case.
Example: Etherchannel made of 4 links: 0 - 3.
You need to use to bits to decide which link to use:
00 -> link0
01 -> link1
10 -> link2
11 -> link3
If the 2 bits are taken from the same address (ex.
dest-mac) then you risk that if a destination is more
requested then others the corresponding link will be
overused, while others may remain little to no used at
all.
Taking one bit from the src-mac and one from the
dest-mac (or src-ip, dest-ip) helps the situation,
because to a "common" destination you add the
randomness of different sources.
Remember...if the etherchannel is L3 you never ever
want to use any load balancing that is mac address
based. So src-dest-mac is never appropriate for that
case.
Sabrina
--- Rob McDonald <robmexpert@gmail.com> wrote:
> Sabrina,
>
> Good explanation! I always get confused about case #
> 2. Can you plz explain
> it a little bit more or check to see if I got it
> right.
>
> 2.
> L2 etherchannel
> HostA ----SW1===========SW2-----NetworkB(many hosts)
>
> SW2 has a lot of hosts, whereas SW1 has only one or
> very few hosts.
> So you'll recommend to use:
>
> SW1 - dst-mac
> SW2 - src-mac
>
> There is also another option in 3560s src-dst-mac or
> src-dst-ip.... How do
> you recommend that to use in this scenario?
>
> Thanks,
> Rob
>
>
> On 5/9/07, sabrina pittarel <sabri_esame@yahoo.com>
> wrote:
> >
> > Let me give you some examples...
> >
> > 1.
> >
> > L3 Etherchannel
> > Network--------R2=========R3-------Network
> > A B
> >
> > Will you ever use src-mac or dest-mac load
> balancing
> > on a L3 etherchannel?
> > Of course not! Otherwise you are going to use only
> one
> > etherchannel link for all your traffic
> >
> > 2.
> > L2 etherchannel
> > HostA ----SW1===========SW2-----NetworkB(many
> hosts)
> >
> > You sure don't want to use src-mac or src-ip LB on
> > SW1;
> > or dst-mac/dst-ip on SW2
> >
> > Does this make sense to you?
> >
> > I'm sure if a question like the one you were
> asking
> > pops up in the CCIE lab, the scenario will be vey
> > similar the ones I described above.
> >
> >
> > Sabrina
> >
> >
> >
> >
> > --- Hossam Abbas <habbas97@yahoo.com> wrote:
> >
> > > Hi Guys,
> > >
> > > i have some questions about "Port-channel
> > > Load-balance"
> > >
> > > 1) when using it on ethercahnnel port should i
> put
> > > it on both sides, or i could use it on one
> side??
> > > 2) if in the LAB didn't define what type of
> > > load-balance he needs (src-mac, dest-mac,
> > > src-ip,...)
> > > is there any clue how could i decide which type
> i
> > > use??
> > > 3) if u i choose load-blance type for ex.
> src-mac,
> > > could i use on the other side of the channel for
> ex
> > > dest-mac?? or they must be the same??
> > >
> > > if u want to know what i believe in is: i could
> use
> > > it from one side only, and i could use to
> different
> > > types of load balance from both side
> > >
> > > am i right!!!!!!!!!!1
> > >
> > >
> > >
> > >
> >
> >
>
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