H3C S5600 Series Operation Manual page 354

Operation Manual – Routing Protocol
H3C S5600 Series Ethernet Switches
2) Area border router (ABR)
An area border router belongs to more than two areas, one of which must be the
backbone area. It connects the backbone area to a non-backbone area. The
connection between an area border router and the backbone area can be physical or
logical.
3) Backbone router
At least one interface of a backbone router must be attached to the backbone area.
Therefore, all ABRs and internal routers in area 0 are backbone routers.
4) Autonomous system border router (ASBR)
The router exchanging routing information with another AS is an ASBR, which may
not reside on the boundary of the AS. It can be an internal router or area border router.
Area 1
Internal
Router
Figure 4-2 OSPF router types
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.
When the Type-7 LSAs translator state is Enabled or Elected, the ABR
translates Type-7 LSAs into Type-5 LSAs.
When the Type-7 LSAs translator state is Disabled, the ABR does not translate
Type-7 LSAs into Type-5 LSAs.
RIP
RIP
ASBR
Area 0
ABR
Area 2
4-6
Chapter 4 OSPF Configuration
Area 4
Backbone Router
Area 3