[c-nsp] Re: IP Route Profiling

[Oliver Boehmer (oboehmer)]

> 
> IP routing table change statistics:
> Frequency of changes in a 5 second sampling interval
> -------------------------------------------------------------
> Change/   Fwd-path  Prefix   Nexthop  Pathcount  Prefix
> interval  change    add      change   change     refresh
> -------------------------------------------------------------
> 0         21772     21786    21908    21875      20031
> 1         35        39       0        11         10
> 2         61        48       0        17         8
> 3         14        14       0        2          8
> 4         5         8        0        2          4
> 5         16        12       0        0          5
> 10        4         1        0        0          2
> 15        1         0        0        1          0
> 20        0         0        0        0          0
> 25        0         0        0        0          0
> 30        0         0        0        0          6
> 55        0         0        0        0          5
> 80        0         0        0        0          2
> 105       0         0        0        0          0
> 130       0         0        0        0          0
> 155       0         0        0        0          0
> 280       0         0        0        0          1826
> 
> As I understand this, there were 35 Fwd-path changes in the last five
> seconds, 60 in the previous five seconds, 14 in the previous five
> seconds, and so on. My understanding of this *must* be wrong, so
> someone please explain to me how to read this. :)

taking the line:

> 1         35        39       0        11         10

Since profiling was activated, there where 35 five seconds interval
where only one path changed, 39 intervals where one path was added. 11
intervals where the pathcount changed for one path and 10 intervals
where one prefix was refreshed.

The line

> 5         16        12       0        0          5

tells us that there were 16 intervals when 5 prefixes where changed, 12
intervals when 5 prefixes were added and 5 intervals when 5 prefixes
were refreshed.
 
> Another reason I know I can't be reading this right is because there
> are a bunch of Prefix refreshes that are bunched up in interval 280
> and that really doesn't make sense.

As mentioned in my previous mail: This line tells us that there were
1826 intervals where around 280 prefixes were refreshed. Which routing
protocols are you using on the box?

	oli