Very good video: https://www.youtube.com/watch?v=cM3OI_ZyRuQ&ab_channel=CCIEQuickStudy
totally stubby area
You can convert
A stub area that only allows routes internal to the area and restricts Type 3 LSAs
from entering the stub area is often called a
3 to a totally stubby area by configuring the ABR
to only advertise and allow the default route to enter into the area.
set protocols ospf area 07 stub
stub default-metric 10Not-So-Stubby Area or NSSA
You can convert
| ABR | All other Router in the Area | ASBR | ||
|---|---|---|---|---|
| Stub Area | Only local and other area ( no external route ) | set protocols ospf area 0.0.0.7 stub | set protocols ospf area 0.0.0.7 stub | |
| Totally Stubby Area |
from entering the stub area is often called a
only local + default (no ext and other Area route ) default-metric ( adv 0/0 ) + no-summaries ( no LSA3) | set protocols ospf area 0.0.0.7 stub no-summaries + | set protocols ospf area 0.0.0. |
to only advertise and allow the default route to enter into the area.
set protocols ospf area 07 stub
| 7 stub | ||
| Not-So-Stubby Area or NSSA | On area border routers only, for a not-so-stubby area (NSSA), inject a default link-state advertisement (LSA) with a specified metric value into the area. The default route matches any destination that is not explicitly reachable from within the area. | set protocols ospf area 0.0.0.7 nssa default-lsa default-metric 10 |
only default route:
| set protocols ospf area 0.0.0.7 |
| nssa | ||||
