I'm trying to figure out how OSPF establishes routes when used on a network with firewalls.
Say I have four routers (A, B, C, and D) and two firewalls (F1 and F2), arranged like so:
(LocalA) A - F1 - B - C - F2 - D (LocalD)
Say F1 blocks all traffic from LocalA except that which is coming from or destined for LocalD. F2 does likewise for LocalD, effectively allowing them to communicate only with each other. If OSPF were enabled on all routers, B and C would know about each other. B and C would, however, not know about either A or D (I'm assuming). The question is, would A and D know about each other?
And by "know about each other," I mean would one be reachable from the other based on the routing tables that OSPF sets up.
Obviously this question betrays a general lack of understanding about how OSPF works, but bear with me.