The broadcast keyword is used for broadcast and multicast traffic. Frame-relay doesn't support broadcasts, so the keyword allows for it to emulate broadcasts, if you will. It's generally used for routing protocols like OSPF.
You can run any type of network in OSPF over frame relay, the broadcast key-word just allows the multicast (which is used by EIGRP and RIPv2 as well) that is destined to 22.214.171.124 and 126.96.36.199 (both of those are for OSPF depending on the network type).
Without the broadcast keyword you would have to use a neighbor statement, which converts the routing updates typically sent via multicast, to a unicast packet.
When you say "network" types, you could be referring to the OSPF network types stub networks, not so stubby areas, total stub area etc. Or you could be referring to broadcast networks, non-broadcast networks, non-broadcast multiaccess networks etc.
Either way, the broadcast keyword allows for neighbor adjacencies between routing protocols and routing updates. It is not always needed, and there are other ways to get the updates, such as using PPP over frame-relay.
Broadcast Network - An example of a broadcast network is an ethernet network, a broadcast is a packet that is destined to all hosts, we typically use VLAN's to segment broadcast traffic. Routers use broadcasts for some routing protocols such as RIPv1.
In regards to frame-relay and OSPF in particular, broadcast also refers to multicast traffic. OSPF uses multicast as opposed to broadcasts to send routing information to other routers. Without the broadcast keyword, the routing updates would never be sent out a frame relay interface.
Non-broadcast Networks - An example of a non-broadcast network is frame-relay, in order to overcome this limitation that affects routing updates, you can either specify "broadcast" in the interface configuration of frame-relay, or specify a neighbor in the routing protocol:
router ospf 1
This would then send unicast routing updates instead of multicast routing updates.
Non-broadcast multi access Networks - Very similar to the frame-relay example, with the exception that it would use a virtual interface instead of a physical interface. To configure a virtual interface you could use something such as:
interface virtual-template 1
ip address 10.10.10.1 255.255.255.0
There really is a lot that is involoved with this subject.
Here is a link that discusses OSPF and multi-access networks:
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.