Articles

Video 12: Implementing OSPF over NBMA

In Uncategorized on April 21, 2011 by carlosfvc

OSPF Network Types

Broadcast, multi-access networks

Example: Ethernet, Token Ring
Single operation mode
DD/BDR election, 10 sec, Hellos, Dual Multicast ADD

Point-to-Point netwroks

Example: T1, ISDN BRI/PRI
Single operation mode
No DR/BDR, 10 sec. Hello, single multicast add

Non-broadcast multi-access (NBMA) networks

Example: Frame Relay, ATM
Five modes of operation

NBMA Topologies

Hub-and-spoke
– No redundancy
– Latency is high
– Cheap

Partial Mesh

Full Mesh
– High cost
– Full redundancy

OSPF over NBMA: Five Modes

– Non-broadcast (NBMA) – RFC Standard

Default mode for x.25, FR, ATM
Neighbors statically configured
Must be one subnet
Acts like a LAN enviroment
DR/BDR rlrcted (must have full connectivity)

– Point-to-multipoint – RFC

Fixes issues with NBMA networks
Requires single subnet
No DR/BDR elected
Neighbors automatically form

– Point-to-Point (cisco)

Uses Separate sub-interface
Requires different subnets
No DR/BDR elected
Neighbors auntomatically form

– Broadcast (Cisco)
– Point-to-multipoint , non-broadcast (Cisco)

Fixes issues with NBMA networks
Requires single subnet
No DR/BDR elected
Statically neighbors forming

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: