[c-nsp] Converting OSPF backbone to iBGP

[Garry]

Oh, and some more (final?) thoughts/questions:

On core/backbone routers, I use "redistribute connected subnets" to
ensure link (transfer) networks being made known throughout area 0,
while the other processes/areas do not have any redistribute activated
on P(E) routers. This will, of course, also insert LAN links into the
OSPF announcements. I'm trying to find a reason for or against that
being problem or undesirable ... :)

But another thing is more of a problem I guess. Gert stated correctly
that overlapping OSPF areas on a single interface need to be avoided
(most likely as it won't work ;) )... so then how do I keep OSPF routes
from non-BGP-speaking devices out of my area 0? As mentioned earlier in
the thread, I have some devices (namely ISDN PRI routers) that do not
speak BGP (and due to low volume, I do not intend to replace them with
Cisco gear), as well as leased-line xDSL routers, usually hooked up into
our POP LANs via OSPF. For leased lines, I could still go static routes,
but that would cause problems for sites that have a backup link via
another DSL link. For the ISDN dialins, with the devices being hooked up
to our POP LAN, and the (i)BGP speakers also communicating there with
OSPF in order to distribute link IP networks, it would result in all
dialins being moved into area 0 ... so what to do? Set up a separate
VLAN just for those kinds of devices? Or just take them in (I mean,
we're probably talking about a maximum of 20 or so dynamic routes peak,
plus another 20-30 from the leased lines ...)?

Tnx, -garry