[c-nsp] per flow load balancing

[Rodney Dunn]

It will do L4 hasing for IPV4 in hardware.

mls ip cef load-sharing full

To set CEF load balancing to include Layer 4 ports and source IP/destination IP addresses (Layer 3), use the mls ip cef load-sharing full command. Use the no form of this command to return to the default settings.

mls ip cef load-sharing full 



I don't know if when you have this configured and MPLS packets move
through if we'd still do L4 port hashing or just the L3 ip addresses.

Rodney


On Wed, Dec 28, 2005 at 12:36:30PM -0200, Everton da Silva Marques wrote:
> Rodney,
> 
> On Tue, Dec 27, 2005 at 02:22:08PM -0500, Rodney Dunn wrote:
> > On a 65xx/76xx the flexwan's don't do any packet forwarding.
> > 
> > It's all hardware based as long as you don't have a feature
> > on that causes the traffic to be punted.
> 
> Many thanks for the clarification. Then I assume the
> forwarding is performed by the PFC. In such case, there is
> one small doubt that I hope you could bring light upon: I
> can't tell whether the PFC's hardware-based load-sharing
> would ever feed L4 ports into the hashing.
> 
> So far, this is what my research has revealed:
> 
> The document below seems to imply (?) that hardware
> load-sharing for MPLS-labeled packets hashes the output
> interface from exactly the source-destination pair:
>   
>   "If the packet has three labels or less and the underlying
>   packet is IPv4, then the PFC3BXL or PFC3B uses the source
>   and destination IPv4 address." -- http://tinyurl.com/clq35
> 
> That is, under 7600, hardware-based load-sharing for labeled
> packets doesn't seem to consider L4 ports.
> 
> BTW, in the same scenario, do hardware-based load-sharing
> for pure IPv4 packets use L4 ports in the hashing? I have
> found the reference below suggesting (?) that L4 ports don't
> affect the hashing for plain IPv4 packets:
> 
>   "With a PFC (and DFCs, if present), hardware Layer 3
>   switching uses per-flow load balancing based on IP source
>   and destination addresses." -- http://tinyurl.com/bb89s
> 
> Please let me know whether the PFC should be able to
> actually use L4 ports for hardware-based per-flow
> load-sharing.
> 
> Thanks again,
> Everton