The EOS implementation of OSPF uses an alternate Area Border Router (ABR) behavior. This is implemented as an optimization over the standard OSPF so that the packets would not be dropped when a router loses Active backbone connection which could otherwise be successfully forwarded. As per this new behavior, when an ABR loses active backbone connection, it is allowed to consider summary-lsa from non-backbone area during SPF calculation and the subsequent route installation process thus ensuring improved connectivity. The EOS implementation of OSPFv3 also inherits the same behavior.