Why my PC2 cannot ping 172.16.0.11?

[mayank.sharma05]

Hi All,

To begin with, I am learning Cisco networking so apologies if this is a stupid question. I have a following setup.

Now I have configured OSPF on Routers R1, R2 and R3 and I see the OSPF seems to have done its work just fine, have a look:

R1:

O    172.16.0.0/16 [110/128] via 10.0.0.11, 00:53:00, Serial0/0
C    10.0.0.0/8 is directly connected, Serial0/0
O    172.0.0.0/8 [110/192] via 10.0.0.11, 00:53:00, Serial0/0
C    192.168.0.0/16 is directly connected, Ethernet0/0

R2:

Gateway of last resort is not set

C    172.16.0.0/16 is directly connected, Serial0/1
C    10.0.0.0/8 is directly connected, Serial0/0
O    172.0.0.0/8 [110/128] via 172.16.0.11, 00:53:20, Serial0/1

R3:

     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Ethernet0/0
O    172.16.0.0/16 [110/128] via 172.16.0.1, 00:57:26, Serial0/0
O    10.0.0.0/8 [110/128] via 172.16.0.1, 00:57:26, Serial0/0
C    172.0.0.0/8 is directly connected, Serial

Now the client that is connected to R1, has a default gateway of router R1. as shown in the figure above.

This client can ping Router's both interfaces but what i cannot do is to ping anything beyond that, like i cannot ping 10.0.0.11 or 172.16.0.1 even though I can do so from router without any problems.

Am I missing something? Please help!

[Reza Sharifi · Accepted solution]

On R1, is 192.168.0.0/16 added to OSPF?

Can you post "sh run" and "sh ip ospf neigh" from all 3 routers?

HTH

[mayank.sharma05]

Hello Reza,

Thank you very much! you were right; I checked the OSPF neighbour and added 192.168.0.0/16 subnet there which get it working, however I have one questions if you can answer it for me;

Is it necessary to add a specific subnet to the OSPF before any client of that subnet can communicate using OSPF defined routes? Like is it not possible to have a client in subnet 192.168.0.0/16 just ping a 172 subnet without broadcasting it's own location in the network?

thanks again! :)

[khishtandar]

hi

you must add all of your interfaces ( networks ) to ospf to advertise them . your 192.168.0.0/24 network must advertise for return path . 

pouya khishtandar

[Reza Sharifi]

Hi,

Yes, you would to advertise the subnet (In this case 192.168.0.0/16) to OSPF in order for it to reach other subnets and be reachable by other subnets.

HTH