1) Cname stands for canonical records which is used to one name into another. it is a kind of resource record which can be used as an alias for another domain. They always point to another domain name, not IP addresses.
2) in order to reduce the total amount of information flowing into any areas, OSPF makes use of stub areas. An stub area contains of a single entry point and exit point or multiple ABR can be used to reach external route destinations.
On the other side. totally stub areas are the ones which keep the LSDB information confied to that very area, along with a default route.
3) IP lease time can be defined the total amount of time the IP address is allocated to you using which with you can communicate. Once the lease time expires the IP is randomly allocated to some different machine. The renewal request for the lease time is done halfway through the lease alloted.
4) Advantages of client server network:
a) Centralization: Access rights and resource allocation is done by Servers.
b) Security : Rules defining security and access rights can be defined at the time of set-up of server.
Advantages of Peer to peer network:
a) P2P is more reliable as central dependency is eliminated.
b) The over-all cost of building and maintaining this type of network is comparatively very less.
Disadvantages of client server network:
You need professional IT people to maintain the servers and other technical details of network.
Disadvantes of peer to peer network:
a) Data recovery or backup is very difficult. Each computer should have its own back-up system.
5) The main purpose of WAN is used to connect machines which are spread at a comparable radius of a city(metro),
The main components for a WAN are routers, switches and modems.
