Non-Broadcast (NBMA) – RFC Standard
- Default mode for X25, FR ARM
- Neighbors statically configured
- All WAN interfaces must all be in same subnet.
- Acts like LAN environment
- DR/BDR elected (DR/BDR must have FULL connectivity to all neighbors i.e. hub must be DR in a hub and spoke style network)
Point-to-Multipoint – RFC Standard
- Fixes issues with NBMA networks – treats cloud like series of P2P links.
- Requires Single Subnet
- No DR/BDR Elected
- Neighbors automatically form (as long as pseudo-broadcasts are enabled*
* frame-relay map x.x.x.x dlci broadcast
Point-to-Point – Cisco Proprietary (normal WAN Point to point style behavior on NBMA)
- Uses seperate sub-interfaces.
- Requires different subnets
- No DR/BDR Elected
- Requires different subnets
- Neighbors automatically form
Broadcast – Cisco Proprietary (Ethernet style behavior on NBMA network)
Point to Multipoint, Non-Broadcast – Cisco Proprietary.
- Fixes issues with NBMA networks
- Requires Single Subnet
- No DR/BDR Elected
- Neighbors do not automatically form
- Might be used where routers do not support pseudo broadcasts
