RE: EIGRP offset-lists...... have i got them all wrong?

Yes offset lists changes the AD of a route, use it to make a route a FS.
if you want to unequal cost load balance then your best bet is delay. It
really isn't that hard to figure out.

Asumming route is a FS,

Take the F route and times its metric by the desired balancing ratio , so
5:1 would be FD x 5 .

Now minus the FD of the FS from the FD x 5 value

Now just divide that value by 256. what ever your answer is apply that to
the incomming interface of the FS as delay.

Easy as pie.

So an example with real numbers

F FD = 10501
FS FD = 15123
Balance value 7:1

F FD X 7 = 73507
F FDX7 - FD FS = 58384

58384 \ 256 = 228 (rounded)

So on the incoming interfaces of the FS route add a delay of 228

Remember to set the varience.

cheers

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of andy
Chisholm
Sent: Saturday, July 04, 2009 10:53 PM
To: ccielab_at_groupstudy.com
Subject: EIGRP offset-lists...... have i got them all wrong?

Hi

I've been playing with offset-lists in eigrp thinking that i had read you
could use them with variance to help load-balance, as a direct alternative
to doing maths and altering the delay on one of the interfaces i wish to
loadbalance through. I thought, for example if i were asked to LB at a ratio
of 5 to 1 it may be quicker in my lab to use offset lists.

However, when i started playing with them, it seems that they alter the
AD/RD of a route rather than just adding to the composite metric. So when
applied to the route i wish to make less preferable (ratio 1) it actually
made the AD so high it couldn't be a feasible successor.

I guess my question is: have i got offset lists all wong? are they used in
this instance to increase the 'composite metric' of a preferred route higher
than the secondary routes' AD/RD? In which case you've still got play with
the delay....

Can anyone explain how they are used properly?

cheers
Andy

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Received on Sat Jul 04 2009 - 23:10:37 ART