On a broadcast network with four routers, all the routers run OSPFv3, and the DR priorities of all the routers are not 0. How many adjacencies are there on the network?
On a broadcast network with four routers, all the routers run OSPFv3, and the DR priorities of all the routers are not 0. How many adjacencies are there on the network?
In a broadcast network with OSPF (Open Shortest Path First) running and four routers where none of the DR (Designated Router) priorities are 0, the OSPF forms adjacencies between the DR and all other routers, as well as between the Backup Designated Router (BDR) and all other routers and the DR. Hence, out of 4 routers, you will have one router as DR, one as BDR, and the other two routers will establish adjacencies with the DR and BDR. This results in a total of 4 + 1 adjacencies, giving us 5 adjacencies.
Wouldn't it be C? 5 adjacencies?
Right answer is C - 5 adjacencies. Formula is n(2)-3. n = number of routers involved.