how many BGP routers, how many ASes

Ray Sanders Ray.Sanders at
Wed May 13 11:19:10 CDT 2009


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Routing Table Report   04:00 +10GMT Sat 09 May, 2009

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Detailed Analysis:

Analysis Summary

BGP routing table entries examined:                              288037
    Prefixes after maximum aggregation:                          136199
    Deaggregation factor:                                          2.11
    Unique aggregates announced to Internet:                     140785
Total ASes present in the Internet Routing Table:                 31199
    Prefixes per ASN:                                              9.23
Origin-only ASes present in the Internet Routing Table:           27142
Origin ASes announcing only one prefix:                           13239
Transit ASes present in the Internet Routing Table:                4057
Transit-only ASes present in the Internet Routing Table:             96
Average AS path length visible in the Internet Routing Table:       3.6
    Max AS path length visible:                                      33
    Max AS path prepend of ASN (43683)                               31
Prefixes from unregistered ASNs in the Routing Table:               461
    Unregistered ASNs in the Routing Table:                         151
Number of 32-bit ASNs allocated by the RIRs:                        142
Prefixes from 32-bit ASNs in the Routing Table:                      30
Special use prefixes present in the Routing Table:                    0
Prefixes being announced from unallocated address space:            194
Number of addresses announced to Internet:                   2039977920
    Equivalent to 121 /8s, 151 /16s and 151 /24s
    Percentage of available address space announced:               55.0
    Percentage of allocated address space announced:               63.7
    Percentage of available address space allocated:               86.4
    Percentage of address space in use by end-sites:               76.9
Total number of prefixes smaller than registry allocations:      142407

On Wed, 2009-05-13 at 16:53 +0100, Irfan Zakiuddin wrote:
> Hi all,
> I have scouted around for this information, but not get very far.  I'm
> hoping someone will have answers at hand.
> What I want to know is roughly how many :
> 1.  ASes there are in the world today?
> 2.  BGP routers there are, for intra-domain as well as inter-domain routing,
> in total in the world?
> 3.  BGP routers do the largest ASes have?
> Really interesting would then be to say either how fast the above numbers
> are growing, or to give estimates for what the answers to 1-3 will be in 5
> years time.
> An Internet source that provides the above information would be most useful
> - though I can't seem to find it with google.
> I'd be grateful for answer to be sent to me directly, whether you also post
> to NANOG is up to you.
> thanks in advance.
> irfan
"Prediction is very difficult, especially about the future." Niels Bohr
Ray Sanders
Linux Administrator
Village Voice Media
Office: 602-744-6547
Cell: 602-300-4344

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