[c-nsp] Per packet Load balancing

Rodney Dunn rodunn at cisco.com
Tue Sep 7 13:53:06 EDT 2004


On Tue, Sep 07, 2004 at 11:08:08PM +0530, Amol Sapkal wrote:
> On Tue, 7 Sep 2004 12:46:33 -0400, Rodney Dunn <rodunn at cisco.com> wrote:
> > On Tue, Sep 07, 2004 at 10:09:59PM +0530, Amol Sapkal wrote:
> > > Seems the post went in too early.
> > > I checked after few minutes, the incoming load balancing doesnt work
> > > now. I think I am missing something.
> > >
> > > This was what was done:
> > > ip cef enabled globally.
> > > Following command added to the physical interfaces which have the
> > > sub-interfaces supposed to 'static load balance' the downlink traffic.
> > >
> > > ip load-sharing per-packet
> > >
> > >
> > > What is it that I am missing?
> > 
> > Put that command on the "ingress" interface that feeds the downstream
> > PVC's.
> > 
> > ie: Your links coming in from the internet.
> 
> Ok. I  put this on the incoming interface ( to Internet) but still it
> didnt seem to load balance. But after I re-put it on the outgoing
> interfaces, it is load-balancing closely( but not as accurately close
> as process switched).
> Any reason for this?

No.  Assuming you had it configured with process switching everywhere
there is absolutely no difference from a load sharing perspective of
that and cef per packet.


> 
> The hash table shows me the 2 outgoing interfaces for each IP of the /28 pool.
> In the 'ip cef accounting' , I dont have the 'load' option.

It's hidden for no reason...just type it.

Then do 'sh ip cef <dstprefix> internal' and see if you are using
equal amounts over the buckets.

> 
> Thanks - Amol
> 
> 
> > 
> > 
> > 
> > >
> > >
> > >
> > > On Tue, 7 Sep 2004 22:04:49 +0530, Amol Sapkal <amolsapkal at gmail.com> wrote:
> > > > Thanks!
> > > > On Tue, 7 Sep 2004 12:20:59 -0400, Rodney Dunn <rodunn at cisco.com> wrote:
> > > > > You shouldn't do it that way.
> > > > >
> > > > > You can configure CEF to do per-packet load
> > > > > balancing.
> > > > >
> > > > > Turn on CEF globally and then on the inbound
> > > > > interface feeding the downstream equal cost paths
> > > > > do "ip load-sharing per-packet".
> > > > >
> > > > > Don't leave it like you have it now.  You are process
> > > > > switching all the traffic.
> > > >
> > > >
> > > > This works, I checked on the client router interface. The incoming
> > > > traffic is load balanced.
> > > >
> > > > Apologies for asking it here (and not reading it myself), what does
> > > > 'ip load-sharing per-packet' actually do?
> > > >
> > > > >
> > > > > Rodney
> > > >
> 
> 
> -- 
> Warm Regds,
> 
> Amol Sapkal
> 
> --------------------------------------------------------------------
> An eye for an eye makes the whole world blind 
> - Mahatma Gandhi
> --------------------------------------------------------------------


More information about the cisco-nsp mailing list