[c-nsp] "show platform hardware capacity" shows sup720-3b FIB table at 98%

[Darrell Root]

Apologies if this is a rerun.  I tried to search for dups.  I figured  
a warning was
timely.

There's a cool new command in 12.2(18)SXF: "show platform hardware  
capacity"

It shows the capacity of all resources on the box.  FIB tables.   
TCAM.  Flash.  Tons of
stuff you never heard of.

Until we upgraded to a sup720-3bxl (very very recently), our  
sup720-3b with full internet routes showed
the following:

L3 Forwarding Resources
              FIB TCAM usage:                     Total         
Used       %Used
                   72 bits (IPv4, MPLS, EoM)     196608       
192900         98%
                  144 bits (IP mcast, IPv6)       32768            
5          1%

                      detail:      Protocol                     
Used       %Used
                                   IPv4                       
192900         98%
                                   MPLS                            
0          0%
                                   EoM                             
0          0%

                                   IPv6                            
2          1%
                                   IPv4 mcast                      
3          1%
                                   IPv6 mcast                      
0          0%


So while the sup720-3b is advertised as being able to handle 256k  
routes, by default
it allocates 64k 32-bit entries to IPv6 and multicast, giving a  
default IPv4 capacity
of 196608 entries.  The Internet route table is almost there.  At the  
current rate of growth
we've got about a month.

I would assume that if we hit 100% that bad things would happen.  The  
cat6k makes
a pretty good 7200 when it forwards in software ;-)

A previous message on this list from Andrew Fort indicates:

> box#show mls cef maximum-routes
> FIB TCAM maximum routes :
> =======================
> Current :-
> -------
>  IPv4 + MPLS         - 192k (default)
>  IPv6 + IP Multicast - 32k (default)
>
> I know you can re-carve this ('mls cef maximum-routes ...'), which
> obviously requires a reboot.


On a sup2 in hybrid mode "show polaris fibmgr usage" shows:


Total FIB entries:        262144
Allocated FIB entries:    193003
Free FIB entries:          69141
FIB entries used for IP ucast:  193002
FIB entries used for IPX     :       1
FIB entries used for IP mcast:       0

So I think my sup2 hybrids are ok.

Question: Are my sup2 native-ios boxes ok?  I can't figure out how to  
verify my free FIB
capacity on my 12.1E boxes.  Anyone know the magic command for that?

Darrell Root
darrellroot at mac.com