Number of entries in routing tables

[Gianluca . Rolandelli]

Hi all.
I have read that an inter domain router (connected to the big Internet) has a
routing table with 42000 entries (this value refers to the end of 1996). I would
like to know if it is possible to estimate the number of entries of an intra
domain router (that has only the knowledge of the destinations of the domain it
belongs to).
Tanks in advance!