Hello everyone, in this tutorial I’ll discuss about ospf area. ospf work with area if we have too many router that running ospf we can divide into several areas. The purpose of area to reduce LSA (Link State Advertisement) deployment on each ospf routers so that the router will only send the LSA to the router in one area and will not send to another area.
The concept of area as the following bellow :
If you see at the image above, ospf routers on area0 only adjacency and advertise those router networks to the router at same area not to different area. implementation area can be reduce router resource and it can be save bandwidth use but every routers just do adjacency to the routers at same area. every area must be have Unique areaID, writting of area id is using 32bit format like a ipv4 address. in the implementation, area is divided into 2 areas :
- Area0 (Backbone Area)
area0 or called as backbone area there is a mandatory area in the OSPF. if you implementation ospf single area, those area must be backbone area and if you implementing multiple area, backbone area must exist because this area is a connecting area to another areas in ospf routing protocol. default format areaid for backbone is 0.0.0.0
- Regular Area
regular area is an area other then backbone area. it can be useful for end device connecting. This area is uncertain areaID so that you can determine of own areaID with keep using areaID format. this area must be direct connection with backbone area.
if we discuss about regular area, that’s divided into some area. it’s called as special area :
- Standar Area
- Stub Area
- Totally Stubby area
- Not So Stubby Area (NSSA)
- Totally Stubby NSSA