doyle ospf chap 4 case stub...

how's your stub...

add router, r5 to the topology...

spin up eigrp, add f0/0 and the loopbacks...

router eigrp 1
 network 1.0.0.0
 network 2.0.0.0
 network 172.16.0.0

m#sh run | beg eigrp
router eigrp 1
 network 172.16.0.0

before redistribution, check the lsa's on r

r#sh ip ospf data data

            OSPF Router with ID (192.168.30.1) (Process ID 10)

Area 1 database summary
  LSA Type      Count    Delete   Maxage
  Router        2        0        0      
  Network       0        0        0      
  Summary Net   2        0        0      
  Summary ASBR  1        0        0      
  Type-7 Ext    0        0        0      
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0      
  Opaque Area   0        0        0      
  Subtotal      5        0        0      

Process 10 database summary
  LSA Type      Count    Delete   Maxage
  Router        2        0        0      
  Network       0        0        0      
  Summary Net   2        0        0      
  Summary ASBR  1        0        0      
  Type-7 Ext    0        0        0      
  Opaque Link   0        0        0      
  Opaque Area   0        0        0      
  Type-5 Ext    0        0        0      
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0      
  Non-self      4      
  Total         5        0        0     

now redistribute...

router ospf 40
 redistribute eigrp 1 metric 1 subnets
 network 192.168.10.0 0.0.0.31 area 192.168.10.0

notice the single type 4 and 3 type 5's in the output... see table above for explanation...

area 1 is not originating external lsa's and is therefore candidate as a stub...

make area 1 a stub...

on routers r and  c add area 1 stub to each configuration...
seems insignificant for a small topology, but in a larger one, the reduction of lsa's could prove useful...

compare after the adjacency change... note the addition of a summary net (type 3) and the elimination of the single type 4 and the 3  5's...

it also now advertises a default route via the added summary lsa...

r#sh ip route | excl L | incl loop

Gateway of last resort is 192.168.30.10 to network 0.0.0.0

O*IA  0.0.0.0/0 [110/782] via 192.168.30.10, 00:07:09, Serial1/1
      192.168.10.0/27 is subnetted, 1 subnets
O IA     192.168.10.0 [110/2343] via 192.168.30.10, 00:07:09, Serial1/1
      192.168.20.0/30 is subnetted, 1 subnets
O IA     192.168.20.0 [110/1562] via 192.168.30.10, 00:07:09, Serial1/1
      192.168.30.0/24 is variably subnetted, 4 subnets, 2 masks
C        192.168.30.0/29 is directly connected, Loopback0
C        192.168.30.8/29 is directly connected, Serial1/1

they remain e2's on router g of course...

g#sh ip route

Gateway of last resort is not set

      1.0.0.0/24 is subnetted, 1 subnets
O E2     1.1.1.0 [110/1] via 192.168.10.2, 00:32:37, Serial1/3
      2.0.0.0/24 is subnetted, 1 subnets
O E2     2.2.2.0 [110/1] via 192.168.10.2, 00:32:37, Serial1/3
      172.16.0.0/24 is subnetted, 1 subnets
O E2     172.16.1.0 [110/1] via 192.168.10.2, 00:32:37, Serial1/3
      192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.10.0/27 is directly connected, Serial1/3
L        192.168.10.1/32 is directly connected, Serial1/3
      192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.20.0/30 is directly connected, Serial1/2
L        192.168.20.2/32 is directly connected, Serial1/2
      192.168.30.0/24 is variably subnetted, 2 subnets, 2 masks
O IA     192.168.30.1/32 [110/1563] via 192.168.20.1, 00:21:10, Serial1/2
O IA     192.168.30.8/29 [110/1562] via 192.168.20.1, 03:49:31, Serial1/2