CCNA Case Study - Static Routes

I'm currently doing the CCNA (Cisco Certified Network Associate) course at school and am a bit stuck on my case study, so I was wondering if anyone could help.

I have the following topology:

I have set up all the connections to the ones shown above. I can ping between R1 and R2, and R1 and R3 using the serial connections. However I couldn't ping between PC1 and R2/R3. Therefore I created a static route as follows:

Router1(config)#ip route 192.168.23.0 255.255.255.0 192.168.12.2

Router2(config)#ip route 192.168.1.0 255.255.255.0 192.168.12.1

I can now ping between PC1 and R2.

However, the next part of the case study asks to ping PC2 and PC3 from PC1, and it should fail. However mine is successful... Is there something else I should have done, or have I gone too far ahead etc?

PC>tracert 192.168.12.2

Tracing route to 192.168.12.2 over a maximum of 30 hops: 

  1   14 ms     6 ms      8 ms      192.168.1.11
  2   *         *         *         Request timed out.

Router1#show ip route

Gateway of last resort is not set

C    192.168.1.0/24 is directly connected, FastEthernet0/0
C    192.168.12.0/24 is directly connected, Serial2/0
C    192.168.13.0/24 is directly connected, Serial3/0

I think you accidentally jumped a couple of steps ahead by adding the static routes :)

My suspicion is that you tried to ping the routers on their 192.168.23.0/24 interface instead of their 192.168.12.0/24 and 192.168.13.0/24 interfaces. R1 doesn't know about the 192.168.23.0/24 network and so doesn't know how to get to it, causing you to need to put static routes in.

You should pull those static routes out of R1 and R2. Then to test connectivity you should ping from PC1 to 192.168.12.2 and 192.168.13.2 that should work since those are connected networks and the router will know how to route to them. Now, when you ping PC2 and PC3 you will not be able to reach them since R1 doesn't know how to get to those networks. You may need to add a route on PC1 for those networks or make R1 the default gateway depending on how you have things setup.