[c-nsp] BGP Cpu

[Euan Galloway]

On Thu, Jun 21, 2007 at 02:40:57PM -0400, Jeff Fitzwater wrote:

> The command to increase the size is ...
> 
> *mls cef maximum-routes ip* "new number goes here"  * NOTE: You must 
> reboot for this to take effect*.
> 
> Ours was 192K and we raised it to 239K.

Tunable to 240k...
http://puck.nether.net/pipermail/cisco-nsp/2006-August/032846.html

On exceeding the limit the max should have logged (possible quite some time 
ago!)...
%MLSCEF-SP-7-FIB_EXCEPTION: FIB TCAM exception, Some entries will be software switched

To see the difference between the software and the hardware I did this...

for i in `seq 24 6` 
 do 
 FIB=`fgrep "/$i " show.mls.cef.txt | wc -l` 
 RIB=`fgrep "/$i " show.ip.cef.txt | wc -l`
 echo "Number of /$i in RIB: $RIB FIB: $FIB" 
done

(where the txt files are literally the output of those commands).

When broken I got something like...

Number of /24 in RIB:  104054 FIB:  104291
Number of /23 in RIB:   16180 FIB:   16230
Number of /22 in RIB:   14935 FIB:   14970
Number of /21 in RIB:   11894 FIB:   11908
Number of /20 in RIB:   13678 FIB:   13678
Number of /19 in RIB:   11987 FIB:   11991
Number of /18 in RIB:    5552 FIB:    5554
Number of /17 in RIB:    3405 FIB:    3405
Number of /16 in RIB:    8939 FIB:    8939
Number of /15 in RIB:     739 FIB:     647
Number of /14 in RIB:     379 FIB:       7
Number of /13 in RIB:     210 FIB:       3
Number of /12 in RIB:     103 FIB:       1
Number of /11 in RIB:      31 FIB:       1
Number of /10 in RIB:      13 FIB:       1
Number of /9 in RIB:       9 FIB:       0
Number of /8 in RIB:      19 FIB:       1

Where's me /8s gone, where's me /8s gone, and generally a bit of a mess.

When OK it was something like...

Number of /24 in RIB:  104466 FIB:  104468
Number of /23 in RIB:   16222 FIB:   16221
Number of /22 in RIB:   14980 FIB:   14980
Number of /21 in RIB:   11913 FIB:   11913
Number of /20 in RIB:   13682 FIB:   13682
Number of /19 in RIB:   11994 FIB:   11994
Number of /18 in RIB:    5557 FIB:    5557
Number of /17 in RIB:    3407 FIB:    3407
Number of /16 in RIB:    8939 FIB:    8939
Number of /15 in RIB:     739 FIB:     739
Number of /14 in RIB:     379 FIB:     379
Number of /13 in RIB:     210 FIB:     210
Number of /12 in RIB:     103 FIB:     103
Number of /11 in RIB:      31 FIB:      31
Number of /10 in RIB:      13 FIB:      13
Number of /9 in RIB:       9 FIB:       9
Number of /8 in RIB:      19 FIB:      18 ( the difference here is just one contains 127.0.0.0/8 and the other doesn't, "reporting issue" :-)
Number of /7 in RIB:       0 FIB:       0
Number of /6 in RIB:       0 FIB:       0

Pretty much the same (seperate run times of the two commands probably 
accounts for some of the difference, there might be other special stuff 
like the loopack that I didn't notice).

-- 
Euan