[j-nsp] L3VPN advertises the directly connected subnet - why?

[Jeroen Valcke]

Hi,

I'm doing some testing with simple plain L3VPNs and ran into some weird
behaviour. At least I think it's weird. Perhaps somebody can enlighten me.

A CE router is exchanging routes with the PE through BGP. These routes
are correctly advertised 'over' the L3VPN towards other CE routers.
However the directly connected subnet between the CE and PE is also
advertised to the other CE routers. 

Why is this? It was my understanding that only the routes learned from
the BGP advertisement from the CE router would be advertised to the
other CE routers.

What's the reasoning behind this behaviour?
Can I alter this behaviour? And if yes, is it safe to do so?

Weirdly enough I've found a Juniper KB [1] which seems to document the
exact opposite behaviour of what I'm experiencing. This KB describes a
case where the directly connected subnet is not advertised over the
L3VPN and how to 'fix' this.

Thanks for any clues.
Kind regards,
-Jeroen-

PS: JunOS version on the PE routers is 9.3R2.8

[1] http://kb.juniper.net/index?page=content&id=KB12430&cat=BGP&actp=LIST

-- 
Jeroen Valcke