OSPF Virtual Link Part 3 (CCNP)
In part 2, Area 2 and virtual links were added to allow it into Area 0. I also setup the right side routers to show what they look like before the four stub types were added. At the bottom of the page are the database-summary entries for the four stub areas.
Area 34: Stub
Area 35: Totally Stubby
Area 36: NSSA
Area 37: Totally NSSA
The sh ip route commands in part 3 no longer have all the entries that part 2 had before the commands were issued. Compare iosv-13 and iosv-14. iosv-14 has no-summary added to the ABR. You will see the same comparing iosv-15 and iosv-16.
Loopback address on each router is 172.20.x.x and fd00:172:20:x::x/64 where iosv-x has x as the router number.
OSPF Router-id is 10.4.x.x for IPv4 with x as the router number
OSPF Router-id is 10.6.x.x for IPv6 with x as the router number
I added the 172.20 ranges for IPv4 and IPv6 to the 60E static route tables.
ABR and ASBR
iosv-7 Sh IP OSPF and Sh IPv6 OSPF showing ABR and ASBR
The four routers below will be changed to all four stub types in the part 3. In the four stub types: stub, totally stubby, NSSA, Totally NSSA certain rules apply:
1.) All four types of stub ABRs don’t flood type 5 external routes in the area.
2.) Only Stub and NSSA ABRs flood type 3 summary LSAs into the area.
3.) Only NSSA and Totally NSSA allow redistribution of External LSAs into stubby areas.