Internet Routing Tables, BGP, and lots of numbers.
Since working for Quova back in 2000, I've watched the default internet routing table grow from ~84,000 routes to 186,545 routes. A great mailing list to subscribe to for keeping abreast of statistics based on BGP summaries is [bgp-stats]. This APNIC page lets you subscribe to [bgp-stats] and you can learn about other APNIC mailing lists on this page.
One of the values I watched was the 'Number of addresses announced to Internet'. Currently it is 1,505,834,848 IP addresses. It was important at the time because Quova attempts to map every public IP address to a physical location. You can see % of available address space allocated, % of address space announced, and % of available address space announced. Anyway, chock-full of sometimes interesting numbers.
Below is a snippet (only the top section) of a single full analysis report:
Analysis Summary
----------------BGP routing table entries examined: 186545
Prefixes after maximum aggregation: 103149
Unique aggregates announced to Internet: 91293
Total ASes present in the Internet Routing Table: 21958
Origin-only ASes present in the Internet Routing Table: 19079
Origin ASes announcing only one prefix: 9097
Transit ASes present in the Internet Routing Table: 2879
Transit-only ASes present in the Internet Routing Table: 69
Average AS path length visible in the Internet Routing Table: 4.5
Max AS path length visible: 24
Prefixes from unregistered ASNs in the Routing Table: 9
Special use prefixes present in the Routing Table: 0
Prefixes being announced from unallocated address space: 10
Number of addresses announced to Internet: 1505834848
Equivalent to 89 /8s, 193 /16s and 55 /24s
Percentage of available address space announced: 40.6
Percentage of allocated address space announced: 59.9
Percentage of available address space allocated: 67.8
Total number of prefixes smaller than registry allocations: 92023
To see the full analysis with all kinds of interesting information, here is the report for Sunday April 16th.
