CCNP ROUTE OSPF NETWORK TYPES NBMA

LAB ON YOUTUBE:  
https://www.youtube.com/watch?v=c3OXKU9fjAU                               

OSPF NETWORK TYPES (NBMA)

When building out an OSPF network you must take into consideration of the internet network types. This is dependent on the layer 2 technology used such as Ethernet, point-to-point T1 circuit, frame relay and even frame relay with no broadcast.

There are five different configurable OSPF network types on a Cisco router, broadcast, non-broadcast, point-to-point, point-to-multipoint and point-to-multipoint non-broadcast.

As a network engineer in the field working with OSPF you must know the differences in the OSPF network types and which types are compatible with one another. Some types will work with each other but you have to adjust the hello/dead timers. With this being said the following list below shows which OSPF network types can inter-operate with each other;

• Broadcast to Broadcast
• Non-broadcast to Non-broadcast
• Point-to-Point to Point-to-Point
• Broadcast to Non-broadcast (adjust hello/dead timers)
• Point-to-Point to Point-to-Multipoint (adjust hello/head timers)                                                                          

• Non-Broadcast
  • The Non-Broadcast network type is the default for OSPF enabled frame relay physical interfaces.
  • Non-Broadcast networks requires the configuration of static neighbors; hello’s are sent via unicast.
  • The Non-Broadcast network type has a 30 second hello and 120 second dead timer.
  • An OSPF Non-Broadcast network type requires the use of a DR/BDR

• Broadcast
  • The Broadcast network type is the default for an OSPF enabled ethernet interface.
  • The Broadcast network type requires that a link support Layer 2 Broadcast capabilities.
  • The Broadcast network type has a 10 second hello and 40 second dead timer.
  • An OSPF Broadcast network type requires the use of a DR/BDR.

• Point-to-Point
  • A Point-to-Point OSPF network type does not maintain a DR/BDR relationship.
  • The Point-to-Point network type has a 10 second hello and 40 second dead timer.
  • Point-to-Point network types are intended to be used between 2 directly connected routers.

• Point-to-Multipoint
  • OSPF treats Point-to-Multipoint networks as a collective of point-to-point links.
  • Point-to-Multipoint networks do not maintain a DR/BDR relationship.
  • Point-to-Multipoint networks advertise a hot route for all the frame-relay endpoints.
  • The Point-to-Multipoint network type has a 30 second hello and 120 second dead timer.

• Point-to-Multipoint Non-Broadcast
  • Same as Point-to-Multipoint but requires static neighbors. Used on Non-broadcast layer 2 topologies.
  • Gives you the ability to define link cost on a per neighbor basis.

• Loopback
  • The default OSPF network type; only available to loopback interfaces.
  • Advertises the interface as a host route; changeable by configuring the interface as point-to-point.

The above section is taken from the site: wonderful site must visit this site.

http://www.freeccnaworkbook.com/workbooks/ccna/configuring-ospf-network-types

Network Type	DR/BDR	Dynamic discovery of Neighbour	Hello/Dead timer	Cisco Proprietary
Non Broadcast	Y	N	30/120	N
Point to Multipoint	N	Y	30/120	N
Broadcast	Y	Y	10/40	Y
Point to Point	N	Y	10/40	Y
Point to Multipoint Non Broadcast	N	N	30/120	N

Lab on Areas: find on youtube link.