OSPF Forward Address
OSPF Forward Address (FA):
works like BGP next-hop for OSPF external routes
advertised only if next-hop is on a not-passive and multiaccess interface
if there's not a route to FA address, route is not installed
FA = 0.0.0.0 --> cost to ABR
FA <> 0.0.0.0 --> cost to FA address
NSSA --> FA is ASBR IP --> remove FA with "area 1 nssa no-summary translate type7 suppress-fa"
only router with highest RID advertises type 5+FA into area 0, remember it when manipulating FA or adding interfaces on ABR
Useful commands:
show ip ospf database external
show ip ospf border-routers
area 1 nssa no-summary translate type7 suppress-fa
###Links
The Effects of the Forwarding Address on Type 5 LSA Path Selection
OSPF Forwarding Address Suppression in Translated Type-5 LSAs