questions about eigrp and ospf route summerization

I have one router that is not being summarized between ospf and eigrp while all other are. If you look at my topology, For ex, R12 ip route, all routes are summarized except 172.20.0.0. BUT, if i go to one of the OSPF routers like R3 far left or R7 bottom, 172.20.0.0 route is summarized. So there is some inconsistency going on between the protocols. But what I don't understand is why all other routes are summarized but just this one particular.

image.jpg
R12#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

D    192.168.13.0/24 [90/2297856] via 10.30.1.1, 01:20:16, Serial0/0
D    192.168.14.0/24 [90/2297856] via 10.30.1.1, 01:20:16, Serial0/0
     172.100.0.0/24 is subnetted, 2 subnets
D       172.100.10.0 [90/3321856] via 10.30.1.1, 01:20:16, Serial0/0
D       172.100.12.0 [90/3321856] via 10.30.1.1, 01:20:16, Serial0/0
     172.10.0.0/16 is variably subnetted, 2 subnets, 2 masks
D EX    172.10.0.0/21 [170/4217856] via 10.30.1.1, 00:37:13, Serial0/0
D EX    172.10.8.1/32 [170/4217856] via 10.30.1.1, 00:37:14, Serial0/0
     172.20.0.0/32 is subnetted, 4 subnets
D EX    172.20.8.1 [170/4217856] via 10.30.1.1, 00:37:14, Serial0/0
D EX    172.20.2.1 [170/4217856] via 10.30.1.1, 00:37:14, Serial0/0
D EX    172.20.4.1 [170/4217856] via 10.30.1.1, 00:37:14, Serial0/0
D EX    172.20.6.1 [170/4217856] via 10.30.1.1, 00:37:14, Serial0/0
     172.30.0.0/16 is variably subnetted, 2 subnets, 2 masks
D EX    172.30.0.0/21 [170/4217856] via 10.30.1.1, 00:37:17, Serial0/0
D EX    172.30.8.1/32 [170/4217856] via 10.30.1.1, 00:37:17, Serial0/0
     10.0.0.0/8 is variably subnetted, 14 subnets, 4 masks
D       10.10.0.0/20 [90/2809856] via 10.30.1.1, 01:20:20, Serial0/0
D EX    10.15.1.0/30 [170/4217856] via 10.30.1.1, 00:37:17, Serial0/0
C       10.30.1.0/30 is directly connected, Serial0/0
D       10.18.1.0/30 [90/3705856] via 10.30.1.1, 01:20:20, Serial0/0
D       10.16.1.0/30 [90/3193856] via 10.30.1.1, 01:20:20, Serial0/0
D       10.21.1.0/30 [90/2681856] via 10.30.1.1, 01:20:20, Serial0/0
D EX    10.45.1.0/30 [170/4217856] via 10.30.1.1, 00:37:17, Serial0/0
D EX    10.32.1.0/30 [170/4217856] via 10.30.1.1, 01:20:20, Serial0/0
D EX    10.67.1.0/30 [170/4217856] via 10.30.1.1, 00:37:17, Serial0/0
D EX    10.100.1.0/24 [170/4217856] via 10.30.1.1, 00:37:17, Serial0/0
D       10.250.0.0/22 is a summary, 01:17:29, Null0
C       10.250.1.0/24 is directly connected, Loopback1
C       10.250.2.0/24 is directly connected, Loopback2
C       10.250.3.0/24 is directly connected, Loopback3
     192.168.16.0/32 is subnetted, 1 subnets
D EX    192.168.16.1 [170/4217856] via 10.30.1.1, 00:37:18, Serial0/0
D EX 192.168.0.0/20 [170/4217856] via 10.30.1.1, 00:37:18, Serial0/0

Open in new window

LVL 3
Shark AttackNetwork adminAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

JustInCaseCommented:
OSPF is link state protocol, and it cannot summarize routes inside area. You are summarizing routes on R4 (ABR), routes from area 32 will be summarized when those are advertised to area 0, but you can't summarize those loopbacks of R4 cannot be summarized since those belong to area 32, not to area 0. If those are in area 0 you could summarize those.
You still got plenty of options,like you could summary your routes using EIGRP on R1 router (eigrp could summarize on any interface).
0
Shark AttackNetwork adminAuthor Commented:
how come areas 15 router 43 routes are summarized then? the 172.10.0.0 are summarized on R2 abr
0
JustInCaseCommented:
Anything on the left side of R4 can be summarized while it is advertised to the right. You summarize from direction of area 0 to area 32 (routes from left side are summarized to the right), and from area 32 to area 0 (routes from right side are summarized to the left).
But, you are redistributing on R5 or R1, EIGRP is connected to area 32 and there those routes are inter area routes and can not be summarized while those are area 32. Remember OSPF message types - type one and type two? There is no place for summary there (can't avoid those inside area).
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Shark AttackNetwork adminAuthor Commented:
thanks!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Routers

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.