Module 3- Stub, Totally Stubby, and Not-So-Stubby Areas pptx

 Configuring OSPF Area Types  Using Stub and Totally Stubby Areas  Configuring Stub Area  OSPF Stub Area Configuration Example  Configuring Totally Stub Areas  Totally Stubby Area

Trang 1

BSCI Module 3 Lesson 7 - Stub, Totally Stubby,

and Not-So-Stubby Areas

Trang 2

 Configuring OSPF Area Types

 Using Stub and Totally Stubby Areas

 Configuring Stub Area

 OSPF Stub Area Configuration Example

 Configuring Totally Stub Areas

 Totally Stubby Area Configuration Example

 Interpreting Routing Tables

 Configuring Not-So-Stubby Areas

Trang 3

BSCI

3

Học viện mạng Bách Khoa - www.bkacad.com

Configuring OSPF Area Types

 Standard area: Accepts link updates, route summaries,

and external routes (the default)

Trang 4

Configuring OSPF Area Types

Trang 5

BSCI

5

Using Stub and Totally Stubby Areas

Trang 6

Stub Area

And if type 5 LSAs are not known inside an area, type 4 LSAs are

unnecessary; these LSAs are also blocked

 As in any area, all routers in a stub area must have identical

link-state databases To ensure this condition, all stub routers will set a

flag (the E-bit) in their Hello packets to zero.

 No router within a stub area can be an ASBR.

 Virtual links cannot be configured within, nor transit, a stub area.

Trang 7

BSCI

7

Configuring Stub Area

Trang 8

OSPF Stub Area Configuration Example

Trang 9

BSCI

9

Totally Stub Areas

 The totally stubby area is a Cisco proprietary enhancement that

further reduces the number of routes in the routing table

 A totally stubby area blocks external type 5 LSAs and summary

 Totally stubby areas use a default route to reach not only

destinations external to the autonomous system but also all destinations external to the area

Trang 10

Configuring Totally Stub Areas

Trang 11

BSCI

11

Totally Stubby Area Configuration Example

Trang 12

Interpreting Routing Tables

Trang 13

BSCI

13

Configuring Not-So-Stubby Areas

Trang 14

Trang 15

BSCI

15

Trang 16

Configuring Not-So-Stubby Area Example



Trang 17

BSCI

17

Configuring an NSSA Totally Stubby Area

Example

 A single default route replaces both inbound-external (type 5)

LSAs and summary (type 3 and 4) LSAs into the area.The NSSA ABR, which is router 2, automatically generates the O *N2 default

route into the NSSA area with the no-summary option configured

at the ABR, so the default-information-originate option is not

required.

Trang 18

Verifying All Stub Area Types

Trang 19

Trang 20

 3.7.1 Drag and Drop: ID the Area

– Upon completion of this activity, the student will be able to identify the difference between stub and totally stubby areas in OSPF.

Trang 21

BSCI

21

Self Check

1 Stub vs Totally Stub

2 NSSA vs totally NSSA

3 How to advertise default-route into NSSA

4 How to use default-cost for advertise 0.0.0.0/0

Trang 23

BSCI

23

Q and A

Trang 24

 How Does OSPF Generate Default Routes?

–http://www.cisco.com/en/US/tech/tk365/technologies_tech_not e09186a0080094a74.shtml

 OSPF Not-So-Stubby Area (NSSA)

–http://www.cisco.com/en/US/tech/tk365/technologies_tech_not e09186a0080094a88.shtml

 How OSPF Injects a Default Route into a Normal

Area

–http://www.cisco.com/en/US/tech/tk365/technologies_configur ation_example09186a00801ec9f0.shtml

Trang 25

BSCI

25

Định dạng
Số trang	25
Dung lượng	720,42 KB