Redistribution Notes – AD Manipulation

  • Manipulating administrative distance (AD) is another way to help with a mutual redistribution scenario.
  • EIGRPs has different ADs for internal and external (redistributed) routes
  • OSPF and RIP have the same AD no matter where the route orginated.
  • This means that routes redistributed into OSPF may be used instead of a local RIP route.
    • AD 110 (OSPF) beats 120 (RIP) every time.
  • The distance subcommand allows you to change the AD on specific routes from specific neighbors.
  • This example changes the AD of the route to 10.0.0.0/16 advertised from 1.1.1.1 to 121.
    • This will make this router prefer a RIP route to the same destination.
ip access-list standard RIP-ROUTES
 permit 10.0.0.0 0.255.255.0
!
router ospf 1
 distance 121 1.1.1.1 0.0.0.0 RIP-ROUTES


Corrections are encouraged.

jac