The Hello Protocol
Routers send periodic Hello messages to each other.
The packet contains:
- The router’s selection of the DR and BDR
- Router’s priority used to determine the DR and BDR
- Configurable timers that include:
- Hello Interval – To determine when you should hear from a neighbor
- RouterDeadInterval – The period before a router is declared down
- A list of neighbors the router has heard from
This can be turned off by setting the network to an NBMA.
- This is useful when there is only one router on the cable segment