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Simple OSPF question

webstd.design
Level 1
Level 1

(R1 fa0/0)<--->(fa0/0 R2 s 0/0)<--->(s0/0 R3 fa0/0)<--->(fa 0/0 R4)

R1 fa0/0 - 10.64.0.1

R2 fa 0/0 - 10.64.0.2

R2 s 0/0 - 10.2.1.2

R3 s 0/0 - 10.2.1.1

R3 fa 0/0 - 192.168.34.3

R4 fa 0/0 - 192.168.34.4

Routers R1,R2,R3 are in area 0

Router R4 is configured as ospf area 10.

R3 also configured as ospf area 10.

QUESTION: What should I do to make R4 see all routers in area 0?

Should I use redistribution?

Thank you!

14 Replies 14

Joseph W. Doherty
Hall of Fame
Hall of Fame

There are several ways to accomplish this. Normally, each router would have a network statement or statements within its OSPF routing process that will match against the links you want within the OSPF domain. Then assuming area 10 is a "normal" area, area 0 routes will flow into it across the R3 ABR.

e.g.

R1

router ospf #

network 10.64.0.1 0.0.0.0 area 0

R2

router ospf #

network 10.64.0.2 0.0.0.0 area 0

network 10.2.1.2 0.0.0.0 area 0

R3

router ospf #

network 10.2.1.1 0.0.0.0 area 0

network 192.168.34.3 0.0.0.0 area 10

R4

router ospf #

network 192.168.34.4 0.0.0.0 area 10

Yes. It's helped me.

But why I cann't do this:

R3

router ospf 1

network 10.2.1.1 0.0.0.0 area 0

router ospf 2

network 192.168.34.3 0.0.0.0 area 10

If router R3 configured so, what should I do to make R4 see all router in area 0?

The problem is you're running two different OSPF processes. Try:

R3

router ospf 1

network 10.2.1.1 0.0.0.0 area 0

network 192.168.34.3 0.0.0.0 area 10

*or*

router ospf 2

network 10.2.1.1 0.0.0.0 area 0

network 192.168.34.3 0.0.0.0 area 10

When you run two different processes, R3 sees all information but it's not shared, by default, between processes. You could also do redistribution across the two processes (I think?), but using just one process would be what you would normally do.

Can I use some command that will show me, that

configured router is internal,backbone,ABR or ASBR?

I don't recall any command that you give you information noting such and such a router is an ABR, etc., although you can infer it from much of the show ospf information commands. Show ospf database would list type of LSA information being received from various routers.

And what about ospf procceses? Why I cann't use separtate procceses on ABR for connection areas?

u can use separate processes for ABR but not recomended

Make following changes

On R3

R3(config-router)area 10 stub

On R4

R4(config-router)area 10 stub

command to see ur ABR etc

show ip ospf border-routers

when I configure areas R3|R4 as stub with separated ospf processes

sh ip route - >

C 192.168.34.0/24 is directly connected, FastEthernet0/0

Router4#

can u post sh run for R3 & R4

What is difference between E1 & E2 route in ospf.





If i am put this command than show E1 Router.



Redistribute bgp 1000 metric 200 metric-type 1 subnets



O E1     10.14.1.0 [110/201] via 172.16.1.4, 00:00:25, FastEthernet1/0


If i am put this command than show E2 Router.


Redistribute bgp 1000 metric 200 metric-type 2 subnets


O E2     10.14.1.0 [110/200] via 172.16.1.4, 00:00:02, FastEthernet1/0




E1 calculate external + internal cost.


E2 Calculate only internal.

I have one else question:

what is difference between E1 and E2 OSPF types?

what is difference between E1 and E2 OSPF types?

http://www.thebryantadvantage.com/CCNPBSCIExamE2E1OSPFRoutes.htm

what is difference between E1 and E2 OSPF types?

OE1: This is determined by using the seed metric + the metric to reach the ASBR

OE2: This is determined by using the seed metric only

OE1 ri=outes are preffered over OE2 routes

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