DR and BDR selection

[tushar47]

Dear sir,

In OSPF, DR1 goes down, BDR1 takes charge. I want to know, is new BDR selected or not. Let us say the new BDR is BDR2. Now we have DR1 down. BDR1 actins as DR and BDR2 acting as BDR. Suppose DR1 that went down, is active again. What will happen then???

Thanks in advance.

Tushar

[pkhatri]

Hi Tushar,

When the active DR goes down, the current BDR will be promoted to be the new DR. An election for a new BDR will take place and one of the remaining nodes will become the new BDR.

When the initial DR that went down comes back up, it does not get restored to the DR status. OSPF likes to keep the network as stable as possible and will not depose any existing DRs when a former DR (with possibly a better priority) comes back up. DR and BDR elections only take place when the DR or BDR go down.

Hope that helps - pls do rate the post if it does.

Paresh