Re: What is a reasonable range for global BGP table size?

[Marshall Eubanks <tme () multicasttech com>]

I still don't see where the excess 20K routes come from. Could these be
internal routes from an iBGP ?

BTW, we have similar histograms plotted on
http://www.multicasttech.com/status/cidr.html and given in
http://www.multicasttech.com/status/histogram.cidr.bgp

# cidr_histogram  Unicast  Prefix Size Histogram
# cidr_histogram  Prefix Size | Number of Prefixes | Number of CIDR 
Holes | Number of Addresses | followed by relative PER CENTAGE in order
# cidr_histogram size  # prfx # holes   # addr % prfx % holes % addr
# cidr_histogram
 cidr_histogram   1       0       0          0    0.0     0.0    0.0
 cidr_histogram   2       0       0          0    0.0     0.0    0.0
 cidr_histogram   3       0       0          0    0.0     0.0    0.0
 cidr_histogram   4       0       0          0    0.0     0.0    0.0
 cidr_histogram   5       0       0          0    0.0     0.0    0.0
 cidr_histogram   6       0       0          0    0.0     0.0    0.0
 cidr_histogram   7       0       0          0    0.0     0.0    0.0
 cidr_histogram   8      20       3  335544280    0.0     0.0   28.0
 cidr_histogram   9       6       1   50331636    0.0     0.0    4.2
 cidr_histogram  10       7       2   29360114    0.0     0.0    2.5
 cidr_histogram  11      12       1   25165800    0.0     0.0    2.1
 cidr_histogram  12      36      12   37748664    0.0     0.0    3.2
 cidr_histogram  13      87      28   45612882    0.1     0.0    3.8
 cidr_histogram  14     235      59   61603370    0.2     0.1    5.1
 cidr_histogram  15     415     102   54394050    0.4     0.2    4.5
 cidr_histogram  16    7270     851  476432180    6.4     1.4   39.8
 cidr_histogram  17    1452     475   47576232    1.3     0.8    4.0
 cidr_histogram  18    2647     846   43363154    2.3     1.4    3.6
 cidr_histogram  19    7672    2205   62833680    6.8     3.7    5.2
 cidr_histogram  20    7429    2680   30414326    6.6     4.5    2.5
 cidr_histogram  21    5212    3146   10663752    4.6     5.3    0.9
 cidr_histogram  22    7929    5330    8103438    7.0     9.0    0.7
 cidr_histogram  23    9682    6619    4937820    8.6    11.2    0.4
 cidr_histogram  24   62823   36537   15957042   55.5    61.8    1.3
 cidr_histogram  25      54      51       6804    0.0     0.1    0.0
 cidr_histogram  26      25      23       1550    0.0     0.0    0.0
 cidr_histogram  27      31      31        930    0.0     0.1    0.0
 cidr_histogram  28      30      28        420    0.0     0.0    0.0
 cidr_histogram  29      16      16         96    0.0     0.0    0.0
 cidr_histogram  30      79      76        158    0.1     0.1    0.0
 cidr_histogram  32      31      29         31    0.0     0.0    0.0


Note that you (or route views) sees 10K more /24 than we do, 3K more 
/23's, etc.

Regards
Marshall


Jared Mauch wrote:

> On Thu, Jul 18, 2002 at 11:11:18AM -0600, Kris Foster wrote:
>
> > That number is still too high since some people are advertising their /25 to
> > /32 prefixes to the route-views box..
>
>         true, but unless you do ingress filtering of your upstream
> (which most smaller ASes do not do) your numbers may be
> wrong.  People also leak internal routes to route-views at
> times also i've noticed.
>
>         (still talking about the same route-views snapshot)
>
> count netmask
> % cut -d: -f2 oix.home_as.out | cut -d/ -f2 | sort -n | uniq -c
>   25 8
>    6 9
>    7 10
>   12 11
>   36 12
>   99 13
>  269 14
>  514 15
> 9764 16
> 1537 17
> 2778 18
> 8378 19
> 8131 20
> 6075 21
> 9949 22
> 12258 23
> 73921 24
>  468 25
>  419 26
>  354 27
>  378 28
>  241 29
>  225 30
>  105 32
>
>         - jared
>
>
> > Kris
> >
> >
> >
> > > -----Original Message-----
> > > From: Jared Mauch [mailto:jared () puck Nether net]
> > > Sent: Thursday, July 18, 2002 12:47 PM
> > > To: Robert Boyle
> > > Cc: nanog () merit edu
> > > Subject: Re: What is a reasonable range for global BGP table size?
> > >
> > >
> > >
> > >         I was going off my data analysis of
> > > route-views data.
> > >
> > > wc -l oix.home_as.out
> > >  135949 oix.home_as.out
> > >
> > >         this file has prefix:home_asn
> > >
> > >         (where home_asn is the last asn in the as_path.  prefixes
> > > with inconsistent home_as will appear twice.  this may be 
> > > cause of some
> > > of your confusion.  eliminating those brings it to 120131 prefixes)
> > >
> > >         - jared
> > >
> > > On Thu, Jul 18, 2002 at 12:37:09PM -0400, Robert Boyle wrote:
> > >
> > > > At 11:26 AM 7/18/2002 -0400, you wrote:
> > > >
> > > > > Hmm.
> > > > >
> > > > > We don't filter, and
> > > > >
> > > > > 112942 network entries and 391859 paths using 25288182 
> > > bytes of memory
> > >
> > > > We don't filter either and...
> > > >
> > > > 117800 network entries and 339843 paths using 23660948 
> > > bytes of memory
> > >
> > > > "about 135k prefixes last i checked." is not what we see 
> > > here from any of 
> > >
> > > > our upstreams.
> > > >
> > > >
> > > > -Robert
> > > >
> > > >
> > > >
> > > >
> > > > Tellurian Networks - The Ultimate Internet Connection
> > > > http://www.tellurian.com | 888-TELLURIAN | 973-300-9211
> > > > "Good will, like a good name, is got by many actions, and 
> > > lost by one." - 
> > >
> > > > Francis Jeffrey
> > > --
> > > Jared Mauch  | pgp key available via finger from jared () puck nether net
> > > clue++;      | http://puck.nether.net/~jared/  My statements 
> > > are only mine.


--
                                 Regards
                                 Marshall Eubanks

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T.M. Eubanks
Multicast Technologies, Inc
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