Re: [mpls-linux-general] hello socket and link failure

[James R. L. <jl...@mi...>]

Sorry for the delay,

On Wed, May 23, 2001 at 06:19:24PM -0700, Scott Lee wrote:
> James,
> 
> Is there any way to know in the socket layer (TCP or
> UDP)
> that whether the physical link has failed?

Ideally we would hear about interface failures via netlink.
Although on Linux lose of carrier is not converted into an
interface state for all drivers.

> I think sendto() does not tell you whether it really
> sent the packet or hold it in the kernel memory.
> If this is the case, the only way we stop sending
> hellos (invoking sendto()) is to let
> the hello timer expires (5sec * 3). Is this correct?

Correct.  On a "real" platform you would get the interface notification
and that would trigger LDP to bring down the adj on that link.

Jim
-- 
James R. Leu