3com 3031 Instruccion De Instalación

C

HAPTER

 40: OSPF C

ONFIGURATION

In OSPF, an AS can be split into multiple areas, whoch puts routers into different 
groups in logical sense.

Perform the following in the OSPF View.

can be input in decimal integers or in IP address format, but only output 

as IP address.

 

 has no default value

Take the area as whole in configuring parameters for the OSPF routers in the same 
area, otherwise information exchange may fail between adjacent routers, or 
routing information may be blocked or routing loop may be generated.

Perform the following configuration in OSPF area view.

You must specify the segment to which the OSPF will be applied after enabling the 
OSPF.

According to RFC2328, after the area division of OSPF, not all the areas are equal. 
In which, an area is different from all the other areas. Its area-id is 0.0.0.0 and it is 
usually called the backbone Area. The OSPF routes between non-backbone areas 
are updated with the help of the backbone area. OSPF stipulates that all the 
non-backbone areas should maintain the connectivity with the backbone area. 
That is, at least one interface on the ABR should fall into the area 0.0.0.0. If an 
area does not have a direct physical link with the backbone area 0.0.0.0, a virtual 
link must be created.

If the physical connectivity cannot be ensured due to the network topology 
restriction, a virtual link can satisfy this requirement. The virtual link refers to a 
logic channel set up through the area of a non-backbone internal route between 
two ABRs. Both ends of the logic channel should be ABRs and the connection can 
take effect only when both ends are configured. The virtual link is identified by the 
ID of the remote router. Transit area provides the ends of the virtual link with a 
non-backbone area internal route. The ID of the transit area should be specified 
when making configuration.

The virtual link is activated after the route passing through the transit area is 
calculated, which is equivalent to a p2p connection between two ends. Therefore, 
similar to the physical interfaces, you can also configure various interface 
parameters on this link, such as hello timer.

Table 562   Entering OSPF area view

Enter OSPF area view

Delete a designated OSPF area

Table 563   Specifying the interface

Specify an interface to run OSPF

Disable OSPF on the interface

.