OSPF Classes of Routers 219
·
Broadcast multiaccess network--Supports multiple routers and can address a single
physical message to all attached routes. Ethernet, FDDI, and Token Ring are examples of
broadcast multiaccess networks.
·
Nonbroadcast multiaccess (NBMA) network--Supports multiple routers and does not
address a single physical message to all routers. Frame Relay and X.25 are examples of
NBMA networks.
·
Point-to-multipoint network--Supports multiple routers. Designated and backup
designated routers are not used with point-to-multipoint networks.
Figure 7-2
OSPF Network Types
OSPF Classes of Routers
There are four classes of OSPF routers:
·
Internal router--All routers that are completely contained within the same area.
·
Area Border Router (ABR)--A router that attaches to more than one area.
·
Backbone router--A router that connects to the backbone. The backbone router has at
least one interface attached to Area 0. The ABR can also be a backbone router.
Frame
Relay
Point-to-point
Broadcast
multiaccess
Nonbroadcast
multiaccess
87200333.book Page 219 Wednesday, August 22, 2001 2:37 PM