Hello,
1)What are Psuedo Broadcasts?
This name is, to my knowledge, not commonly used. What you call "pseudo broadcasts" are normal broadcast or multicast packets replicated by the sending router on all Frame Relay virtual circuits which have the broadcast flag set in the IP/DLCI mapping. In other words, from the Frame Relay viewpoint, there is no difference at all in frame format or in its forwarding. A pseudobroadcast is simply a packet that has been replicated onto many VCs by the router that is forwarding this packet.
2) While configuring the static mapping,if we dont configure the
"frame-relay map ip 1.1.1.2/1.1.1.1 102 broadcast" command and if we configure like
"frame-relay map ip 1.1.1.2/1.1.1.1 102 " i.e without broadcast keyword, then there wont be EIGRP neighborship formed
That is correct. EIGRP by default uses multicast packets sent to 224.0.0.10 to discover neighboring routers, maintain adjacencies and exchange routing information. If the IP/DLCI mapping does not contain the broadcast flag, no EIGRP packet sent to 224.0.0.10 will be replicated through that DLCI. As a result, routers will be unable to exchange EIGRP packets and an adjacency will not form.
unless we configure neighbors statically using
"neighbor 1.1.1.2 serial 1/0" command.
That command, as you can see, defines a neighbor statically - i.e. it will not be discovered by sending multicast IP packets, but instead, you personally told your router what is the normal unicast IP address of the neighboring router. This configuration forces the EIGRP to stop sending multicast EIGRP packets through the interface Serial1/0 altogether, and instead, to send EIGRP packets directly to 1.1.1.2. Therefore the adjacency will come up because there is no multicast configuration on the FR PVC and thus no broadcast flag is necessary.
Best regards,
Peter
