arden ospf filters, take 3....

nice database...

R5#sh ip ospf data

            OSPF Router with ID (5.5.5.5) (Process ID 1)

        Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Link count
3.3.3.3         3.3.3.3         1646        0x80000004 0x001133 2
4.4.4.4         4.4.4.4         1611        0x80000003 0x0037CE 3
5.5.5.5         5.5.5.5         1609        0x80000005 0x008F64 3

        Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum
10.1.34.3       3.3.3.3         1712        0x80000001 0x005091
10.1.35.3       3.3.3.3         1646        0x80000001 0x007765
10.1.45.4       4.4.4.4         1610        0x80000001 0x0003C6

        Summary Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum
1.1.1.1         3.3.3.3         1769        0x80000001 0x001516
2.2.2.2         3.3.3.3         1769        0x80000001 0x00E640
3.3.3.3         3.3.3.3         1769        0x80000001 0x00AE75
10.0.12.0       3.3.3.3         1769        0x80000001 0x003CDC
10.0.13.0       3.3.3.3         1769        0x80000001 0x0027F1
10.0.23.0       3.3.3.3         1769        0x80000001 0x00B856
R5#

permit  the 3.3.3.3 route...

R5#config t
Enter configuration commands, one per line.  End with CNTL/Z.
R5(config)#access-list 1 permit 3.3.3.3
R5(config)#router ospf 1
R5(config-router)#distribute-list 1 in
R5(config-router)#end
R5#
*Nov 18 12:34:29.983: %SYS-5-CONFIG_I: Configured from console by console
 

R5#sh ip route | excl L | incl loop
 

Gateway of last resort is not set

      3.0.0.0/32 is subnetted, 1 subnets
O IA     3.3.3.3 [110/2] via 10.1.35.3, 00:00:18, FastEthernet1/0
      5.0.0.0/32 is subnetted, 1 subnets
C        5.5.5.5 is directly connected, Loopback0
      10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C        10.1.35.0/24 is directly connected, FastEthernet1/0
C        10.1.45.0/24 is directly connected, FastEthernet1/1

the implicit deny all, in action... this is very exciting... he goes on to explain that the database has not been changed by our distribute-list...

the upshot...

So the distribute-list command doesn’t affect routes as they enter or leave the OSPF topology database. The distribute-list command affects routes as they go in and out of the routing table. It does not prevent link state packets from being propagated.


R5#sh ip ospf data

            OSPF Router with ID (5.5.5.5) (Process ID 1)

        Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum Link count
3.3.3.3         3.3.3.3         133         0x80000005 0x000F34 2
4.4.4.4         4.4.4.4         31          0x80000004 0x0035CF 3
5.5.5.5         5.5.5.5         1902        0x80000005 0x008F64 3

        Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum
10.1.34.3       3.3.3.3         133         0x80000002 0x004E92
10.1.35.3       3.3.3.3         133         0x80000002 0x007566
10.1.45.4       4.4.4.4         31          0x80000002 0x0001C7

        Summary Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#       Checksum
1.1.1.1         3.3.3.3         133         0x80000002 0x001317
2.2.2.2         3.3.3.3         133         0x80000002 0x00E441
3.3.3.3         3.3.3.3         133         0x80000002 0x00AC76
10.0.12.0       3.3.3.3         133         0x80000002 0x003ADD
10.0.13.0       3.3.3.3         133         0x80000002 0x0025F2
10.0.23.0       3.3.3.3         133         0x80000002 0x00B657