I was just chatting to Niall about RIPE assignments and members and he gave me a nice little command to check data.
You need to run this in a shell:
whois -i origin AS39122 -h whois.ripe.net
If the RIPE member in question has been keeping their data current you should get back information on all their IP assignments (or is that allocations? I always mix them up!)
Might be helpful to mention that to get the AS number for an ISP, you can do a whois on any of their IP addresses. The AS number will be the origin field.
The above command does an inverse lookup on the origin field.
True. I should have included something about that.
Thanks!