consider there are three routers R1( prio 4 , DR) , R2(prio 3, BDR), R3 (Prio 2, DROther).Consider another router R4(Prio 5) has joined this network.Since DR/BDR is alive, R4's higher priority won't affect the network.What happens if DR goes down, in that case the DR/BDR election resumes, in that case how it chooses DR ? since R4 is of higher priority than R2(prio 3, BDR).
All routers will eventually discover that the DR is down - during the transition, the choice of DR/BDR by a router could change a few times. All routers will eventually get a common understanding of the DR/BDR.
When a router stops hearing Hellos from the DR, it considers that the DR is down and runs the election process. The election process first elects the BDR. If a BDR already exists, then a new BDR is not selected; the existing BDR remains. Then, the election process tries to elect the DR. If there are no routers that have elected themselves DR at that point (which is the case you have), it will promote any existing BDR to DR. Then, it will re-run the process to elect the DR. The former BDR is now the DR so no BDR exists now. Therefore, the router with the highest priority is made BDR.
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.