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OSPF Community Varieties – Non Broadcast

OSPF Community Varieties: Non-Broadcast Multicast

While you construct a routed community utilizing OSPF as your routing protocol of alternative you must take into accounts the truth that OSPF will robotically detect the Layer 2 encapsulation sort and undertake one among 6 methods to function on that hyperlink 모바일 개인방송.

The primary of those 6 behaviours which we’ll cowl is OSPF Non-Broadcast mode

This Non-Broadcast mode is the default state that OSPF will set an interface to once you execute the command “encapsulation frame-relay” on a serial interface.

OSPF will take into account this media like every other broadcast media comparable to Ethernet.

NBMA clouds are often inbuilt a hub and spoke topology. PVCs are specified by a partial mesh and the bodily topology doesn’t present the multi entry that OSPF believes is on the market.

OSPF on this mode will try and additionally elect a Designated Router and a Again Designated router. The number of the DR and BDR the can change into a problem as a result of the DR and BDR must have full bodily connectivity with all different OSPF routers that exist within the Non-Broadcast community. In case you have a hub and spoke community had been one router has Body Relay PVC’s to every spoke then logically you’d configure the Hub to be the DR and the spokes to not take into account themselves as a part of the election course of. To do that you will need to configure the spokes with the next command: (Assuming we’re utilizing the bodily interface)

interface serial zero

ip ospf precedence zero

On the Hub router to be on the protected aspect set the next command so that it’ll change into the DR. (Assuming we’re utilizing the bodily interface)

interface serial zero

ip ospf precedence 255

OSPF is not going to ship any Multicast visitors over the Non-Broadcast media and because of this you will want to configure the DR with (And BDR when you have one)a static record of all different routers connected to the Non-Broadcast community, within the instance beneath our neighbors are 10.1.1.2 and 10.1.1.three.

To do that you will want to make use of the next command:

router ospf 1

neighbor 10.1.1.2 10

neighbor 10.1.1.three 10

The “poll-interval” is the period of time an NBMA interface waits earlier than polling (sending a Hiya) to a presumably useless neighbor. The neighbor command applies to routers with a possible of being DRs or BDRs (interface precedence not equal to zero).

Additionally OSPF will change the interface timers to 30 second Hiya and 120 Useless Timer.