What Jeff is refering to is the fact that in order to make OSPF operate on NMBA media (like FR) you need extra configuration to discover neighbors; the use of the 'neighbor' command. When you configure this command the OSPF messages are unicast to the neighbor.
Your understanding is correct for broadcast multiaccess media like ethernet.
That being said there are other ways to configure OSPF on NBMA that basically avoid having to elect a DR and use the neighbor commands. Such mechanism usually require changing the ospf network type to either point-to-point or point-to-multipoint. If you need detailed information on OSPF the following is a great place to start:
you can have more clear idea of DR election in NBMA by reading the jeff doyle vol1 CASE STUDY OSPF OVER NBMA NETWORK...
when you configure neighbour with command neighbour then tehy will transfer the hello in unicast mode...at that time all router will make their static list of router with their interface ip address and the priority and on the base of priority they will elect the DR ...normally in hub and spoke topology you can have to configur you HUB router as a DR so you have to make it priority hight than other because of all router in hub and spoke topology having connectivity with hub router ...
YOU WILL HAVE MORE CLEAR PICTURE AFTER READING THAT CASE STUDY
Hi everyone, I would like to thank you in advance for any help you can provide a newcomer like myself!
Im studying the 100-105 book by Odom and am currently on the topic of Port security. I purchased a used 2960 and I'm trying to follow a...
While deploying a number of 18xx/2802/3802 model access points (APs), which run AP-COS as their operating platform. It can be observed on some occasions that while many of their access points were able to join the fabric WLC withou...
I am going to design and build an LAN network under a tunnel underground with long distance between the switches.
I will have 2 Catalyst switches and 8 Industrial IE3000, and they will be connected with fiber.
For now I am planning on use Layer-2 s...