Re: switching block design

From: Howard C. Berkowitz (hcb@gettcomm.com)
Date: Sun Jun 01 2003 - 15:37:05 GMT-3


At 8:36 PM +0300 6/1/03, Emad wrote:
>Folks,
>I jus want to share a design with you,
>I have two core switches 6513 connected together through two giga
>ports and I have two switches 4507 (each one of them is connected by
>one link to both switches 6513) and each switch 4507 has one vlan
>only configured on it , if I want to have load balancing on the
>switch 4507 to the two switches 6513 , what is more suitable ,
>running ospf between these two uplinks or having HSRP running on the
>two interfaces and how can I do it?
>Please advise

I'm not completely clear what load you are trying to balance. To get
HSRP load balancing, you have to put the hosts into different HSRP
groups.

Any interior routing protocol, or static routes (it's not limited to
OSPF) will load-share according to the interface switching modes on
otherwise equal-cost routes.

Are there relevant L2 solutions here such as UplinkFast or the newer
IEEE methods?

There are many reasons to load balance. Bandwidth utilization can
certainly be one, but is bandwidth a problem on the gig links?
Reconvergence can be faster in some switching modes, but they are
generally the slowest. What problem are you trying to solve?

Load balancing != high availability failover. Sometimes they are the
same, but often they are not.



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