3com 5500-ei pwr Instruccion De Instalación

 

4-6 

Figure 4-2 OSPF router types 

Area 1

Area 2

Area 3

Area 4

Backbone Router

ASBR

RIP

RIP

Internal 
Router

ABR

Area 0

 

 

5)  Type-7 LSAs translator 

A Type-7 LSAs translator takes effect on an ABR. The state of the Type-7 LSAs translator determines 

whether the ABR needs to translate Type-7 LSAs into Type-5 LSAs.  

z 

When the Type-7 LSAs translator state is Enabled or Elected, the ABR translates Type-7 LSAs 

into Type-5 LSAs.  

z 

When the Type-7 LSAs translator state is Disabled, the ABR does not translate Type-7 LSAs into 

Type-5 LSAs. 

1) Backbone 

area 

With OSPF area partition, not all areas are equal. One of the areas is different from any other area. Its 

area ID is 0 and it is usually called the backbone area. Routing information between non-backbone 

areas must be forwarded by the backbone area. Therefore, OSPF requires: 

z 

All non-backbone areas must maintain connectivity to the backbone area. 

z 

The backbone area itself must maintain connectivity. 

In practice, due to physical limitations, the requirements may not be satisfied. In this case, configuring 

OSPF virtual links is a solution. 

2) Virtual 

link 

 A virtual link is established between two area border routers through a non-backbone area and is 

configured on both ABRs to take effect. The area that provides the non-backbone area internal route for 

the virtual link is a “transit area”.