http://www.linux-knowledge-portal.org/de/
Alphabetical Directory of Linux Commands
Private Address Space
The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
We will refer to the first block as "24-bit block", the second as "20-bit block, and to the third as "16-bit" block. Note that the first block is nothing but a single class A network number, while the second block is a set of 16 contiguous class B network numbers, and third block is a set of 255 contiguous class C network numbers.
rpm -qa | grep apache == gibt auskunft über installierte apache dinger