Re: battling with babel and route changes

[Dave Taht <dave.taht@gmail.com>]

On Wed, Jun 22, 2011 at 7:39 AM, Juliusz Chroboczek <jch@pps.jussieu.fr> wrote:

>
> A patch to reflect the metric in the kernel priority has been published
> on this list at some point; I'll not be merging it into Babel, since
> I remain convinced that that's the wrong thing to do.

I agree that it is the wrong thing to do. Babel's metric calculations
are decidedly different than that of other protocols.

However, to clean up the route change...

either maintaining two routes of different priority differing by 1, or
inserting the new route with priority of base+1 and moving it down
after removing the first route, seems like a workable solution, that
can save hundreds of packets at high volumes.

I'm perfectly willing to try implementing either of these approaches
(the latter being far easier than the first) my concern was that by
doing so I'd break something somewhere else, and felt the best
approach was the first, which, as I said, is harder to implement.

>> 1) babel installs ipv4 routes with a metric of 0, ipv6 routes with a
>> metric of 1024
>
> These are apparently the kernel's defaults -- we call the kernel with
> the value 0 in both cases.  You can set the priority with -k (but cannot
> set it to be different between v4 and v6), and if you need any more
> control, use routing tables (-t and -T).
>
> -- Juliusz
>



-- 
Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608
http://the-edge.blogspot.com