Route Maps represent a powerful tool for manipulating ip routes and packets. Route maps are somewhat similar to Access Lists but are more complex and more powerful. This article describe the basics of route maps on Cisco devices, and what they are used for. Route maps are widely used by:

Time-bases ACLs are Access Lists that enable you to restrict or allow resources based on time periods. For example you as a network administrator are asked to restrict web browsing to some particular servers during working hours. To implement  an time based access lists there are few simple steps:

IPv4 addresses are 32 bit addresses divided into 4 octets. In this article we’ll examine how IP addresses are divided into classes and what are they used for. Classful allocation of IP address space wasted many addresses, which exhausted the availability of IPv4 addresses. Today is used  classless addressing system.

Deep understanding of OSPF Link State Advertisments (LSAs) is crucial to understand OSPF behavior. LSAs build up the OSPF link state database (LSDB), and they are exchanged between OSPF enabled nodes. Here you have the list of OSPF LSAs and a short description.