Configuring Route Summary When Routes Are Injected To The Ospf; Creating The Virtual Connections - D-Link xStack DGS-3610 Series Configuration Manual

Chapter 28 OSPF Routing Protocol Configuration
Note
28.2.7 Configuring Route Summary When
Routes Are Injected to the OSPF
When the routes are redistributed from other routing process to the OSPF routing process,
every route is advertised to the OSPF router as a separate link status. If the injected route is
a continuous address space, the autonomous area border router can advertise only one
summary route, thus reducing the size of the routing table.
To configure the external route summary, execute the following commands in the routing
process configuration mode:
Command
DGS-3610(config-router)# summary-address
ip-address mask[not-advertise | tag tag-id | ]
28.2.8

Creating the Virtual Connections

In the OSPF routing area, the OSPF route updates between none-backbone areas are
exchanged via the backbone area, to which all the areas are connected. If the backbone
area is disconnected, you need to configure the virtual connection to connect the backbone
area. Otherwise, the network communication will fail. If physical connection cannot be
ensured due to the restriction of the network topology, you can also meet this requirement by
creating the virtual connections.
Virtual connections should be created between two ABRs. The common area of the ABRs
become the transmit areas. The stub areas and NSSA areas cannot be used as the transit
area. The virtual connections can be seen as a logical connection channel established
between two ABRs via the transit area. On both its ends must be ABRs and configuration
must be performed on both ends. The virtual connection is identified by the router-id number
of the peer router. The area that provides the two ends of a virtual connection with an
internal non-backbone area route is referred to as the transit area, whose number must be
specified at configuration.
The virtual connections will be activated after the route in the transit area has been
calculated (that is, the route to the other router). You can see it as a point-to-point connection,
on which most parameters of the interface can be configured, like a physical interface, for
example, hello-interval and dead-interval.
The ―logical channel‖ means that the multiple routers running the OSPF between the two
ABRs only forward packets (If the destination addresses of the protocol packets are not
28-14
If route summary is configured, the detailed routes in this area will not be
advertised by the ABR to other areas.
DGS-3610 Series Configuration Guide
Function
Configure the external summary route