[f-nsp] CAM and ip net-aggregate or ip supernet aggregate - does it help to free the cam up ? WAS:AW: cam strangeness

[Gerald Krause]

Ok, reading the foundry doc's again very carefully, I understad at least 
one of the problems - it relates to "overlapping networks":

My two IP transfernets between the NI and RTR1/2 ...


                    +----SW1----+------+
                    |           |      |
      UPLINK----NI400          RTR1   RTR2
                    |           |      |
                    +----SW2----+------+

...are subnets of the mysterious /18, so the /18 is a supernet of 
directly connected networks from the NI view, e.g.:

 - directly connected: 212.79.x/24  (via SW1)
 - directly connected: 212.79.y/24  (via SW2)
 - supernet route:     212.79/18 -> RTR1/2

The document

http://www.foundrynet.com/services/documentation/diag/CAM-partitioning.html

describes now what will happen in this situation: per default the router 
will create /32 CAM entries to every needed destination within the 
supernet. But the solution the document suggest makes me not happy 
because it seems that the only way to get rid of the bunch of /32s is 
the way via software/cpu forwarding for some prefixes.


-- 
Gerald