[c-nsp] Per packet Load balancing

[Amol Sapkal]

On Tue, 7 Sep 2004 09:29:14 +0200, Carlson Per <per.carlson at banetele.com> wrote:
> 
> Hi Amol.
> 
> What makes you think loadbalaning will help you here?
> 
> You had one 2M line (CE-R1), which is split up into two 1M lines
> (CE-R1 and CE-R2). The only thing you have accompished so far
> is making the routing more complex, while not increasing the
> available bandwidth for CE.
> 
Here, I need to give you some more data. Actually the connectivity
from R1-CE is not direct. The E1 is actually between 2 FR switches
(Inter city). Moreover, this E1 also carries other traffic (cannot
help this really). The FR switch connectin to CE has another E1
(trunk) to the FR switch connected to R2. Hence the diversion.




> What do you see? Is there some loadbalancing or none at all? What does
> 'ip cef <ip-address>' where <ip-adress> is the /28-net show? An alternative,
> but not the recommended on (see posting from eralier in this list), is
> making CEF load-balance per-packet instead of per-destination.
> 

I do see traffic via R1-R2-CE. But it is less as compared to R1-CE. I
am not exactly aware of the difference in per-packet CEF and
per-destination CEF. Would be grateful for your inputs.


> > After disabling ip cef, I still see that the incoming traffic on CE is
> > not being load balanced.
> 
> That's normal. If you want loadbalancing you must use some protocol that
> supports it, like CEF or OSPF.
> 
> One simple way to loadbalance a bit is:
> 
> R1:
> ip route <IP-host> 255.255.255.255 CE
> ip route <IP-net> 255.255.255.240 R2
> ip route <IP-net> 255.255.255.240 CE 250
> 
> R2:
> ip route <IP-net> 255.255.255.240 CE
> 
> where <IP-host> is the host you are talking about, and <IP-net>
> is the full IP-network at CE.
> 
> This will dedicate one of the 1M lines for traffic to the
> host, while the onther line is used for all other hosts.
> A floating route on R1 is added for redundancy (if R2 is
> no longer reachable from R1).
> 
> Per
> 
> 

Yes, this was thought of initially, but seeing that 1 IP of the /28 at
times, pulls up almost 90% of the 2 Megs, made me drop the idea.



-- 
Warm Regds,

Amol Sapkal

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