I would like to block access from IP addresses allocated to specific organizations. That is, I know the names of the organizations but not the IP addresses allocated to computers of users accessing the Internet from within the organization. If I query RIPE with the organization name, I do not get the IP addresses assigned to it. Thanks!
Andrew
You could start by doing a MX or NS lookup for their domain. If they administrate their own mail and / or DNS servers you might get lucky, otherwise you'll be stuck with their providers IP space.
Good luck.
Peter
Start with a DNS lookup of the obvious names - their mail, web. DNS servers and so on, and determine who "owns" those addresses. Depending on the size of the organization, you may also be able to determine other magic keys, but the task may not be an easy one, and searching in a clumsy or heavy-handed fashion may cause complaints about you.
Several possible answers - the most obvious being that RIPE is not the authoritative agency. Addresses are also allocated to organizations by National Internet Registries (NIR), and Local Internet Registries (LIR) and these assignments are not reported back to RIPE, which is a Regional Internet Registry (RIR). The block may not have been allocated out of the European Region that RIPE supports. For example, Italy has 769 blocks allocated out of RIPE, but also 4 _other_ blocks allocated from ARIN.
The RIPE 'whois' database is also less searchable than some. This may be out of privacy concerns, or abuse prevention.
If the organization is a source of network abuse, you may also be able to find the address ranges by searching the
, Old guy
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