Re: [B.A.T.M.A.N.] [Battlemesh] Battlemesh v5 tests

Gabriel Kerneis
2012-03-09T11:12:03Z

Hey Simon,

On Fri, Mar 09, 2012 at 09:56:36AM +0100, Simon Wunderlich wrote:
> 1) The detection part is batman-specific, we use the the PRIMARIES_FIRST_HOP flag
> to do that. As a reminder (that might be documented somewhere else):
>
> * OGMs from the primary interface are broadcasted on ALL interfaces and are spread over
> the mesh (big TTL) --> these get the PRIMARIES_FIRST_HOP flag, which is cleared
> when forwarded by other nodes
> * OGMs from the secondary interfaces are only broadcasted on their respective interface
> and are only used for local link sensing (TTL = 1)
>
> When we receive OGMs with PRIMARIES_FIRST_HOP flags on different interfaces, we know
> that it came from the same neighbor, just from different interfaces. We have two
> links to this neighbor.

I think my primary misunderstanding comes from this concept of “primary
interface”. It might be due to my lack of knowledge about Batman, but it
definitely looks like a hack to me: why do you need this symmetry breaking in
the first place?

I believe the rest is only implementation details layered on top of this
assumption.

Maybe there is some explanation that I have overlooked in the wiki? I have not
found, for instance, how the primary interface is chosen.

Best regards,
--
Gabriel