> What does:
> bgp deterministic-med
> do?
> Appears to be undocumented even so that altavista can't find it.
Hmm. I can't profess to detail this exactly, but my understanding
is that 'bgp deterministic-med' has to do with a case similar to
the following:
suppose we have 4 routes with AS paths:
3549 44
3549 44
3549 32
3549 22
In the 'default' state, according to a non-deterministic order,
the routes will be compared.
If sequentially we come upon a set of AS paths that are identical,
it is then determines which is preferred. It then uses that.
In the 'bgp deterministirc-med' case, the routes are sorted in a
deterministirc med.
There's something else in there about like what to do if we have 2
pairs of routes with the same AS, like:
3549 44
3549 44
3549 22
3549 22
Where it does the best of the two, then compares them through the
BGP process.
I suppose I'm just confusing folks, but it basically has to do
with the way routes are compared w/ MEDs.
Smart cisco bgp people could detail this exactly.
> Does
> it per-chance compare MEDs only if the *whole* AS Path is indentical,
> not merely the first AS?
I don't believe so.
My understanding is that by default, the MEDs are compared only
when the *whole* AS Path is identical.
The command 'always compare meds' is what always compares meds,
so long as the BGP AS Path length is the same, irregardless of the
components of the path.
-alan
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