Re: BFD queries

[Dave Katz <[e-mail]>]

On Oct 24, 2005, at 11:14 PM, [e-mail] wrote:

> Hi
>
>
>
> I have following query from the BFD draft
>
>
>
> When a BFD session is established between two nodes in a network,  
> and if one of the system sends a BFD control packet with POLL bit  
> set to change any the Min Tx/Rx intervals and the receives response  
> to the previous BFD packet. This could lead to situation where  
> sender assuming his request for configuration change for Min Tx/Rx  
> intervals is declined.
The intervals cannot be "declined" as they are entirely unilateral in  
each direction (which is an important design consideration in the  
protocol.)  The packet with Final lets the system know that the other  
system has seen the change and, for example, won't time out if the  
sender wants to transmit at a slower rate.

> If the choosen transport protocol for BFD transmission is UDP, the  
> FIN bit set packet is lost then there will be discrepancy the  
> configuration between the configured nodes.
This is why the poll is sent repeatedly until a final is heard.

--Dave