Switch 2 Pc to Switch 3 Pc ping failure

[Lovish]

Hi, I'm trying to ping my PC from the Switch 2 to Switch 3's PC, but it keeps failing. I don't know why. I have attached the file of packet tracer topology in which there are 2 routers, 3 switches, 12 PCs on the left and 12 PCs on the right, which are divided into 6 PCs for 2 switches. In the Topology, on the right side, you can see 6 PCs on the top and 6 PCs on the bottom, and I'm trying to ping from the top pc to the bottom one, but the ping isn't going through. So, if anyone can help me, I would really really appreciate that,
Thank you.

[Joseph W. Doherty · Accepted solution]

The problem is, on the right side, you have the /24 split across two L3 router interfaces.  Either you need to split that /24 into to separate networks, and route between them, or you need to L2 bridge them.

Normally, a Cisco router should throw an error when you have more than one interface in the same network.  But, Packet Tracer is often not fully faithful to real devices.

[Lovish]

I'm using /25 because I need two subnets. it was just, I didn't change the PCs names on the left after changing the subnet mask to .128 from .0 but I'm still getting the ping failure. I have re-attached the file with the correct subnet masks.

[Joseph W. Doherty]

Your new attachment appears to be the same as the original attachment.

[Lovish]

Oh, my bad. Here is the updated file. So, in this, I tried pinging again, but it didn't work right now. Before that, I did work from the PC 192.168.129.121 to 192.168.129.130
Edit: So now I have checked again in the file that was opened from the start. I tried to ping from every PC to every other one on the bottom, all pings went through successfully except the 192.168.129.133 and if I reopen this file, every ping gets failed.

[Joseph W. Doherty]

Works for me, using your latest attachment.

How about a screen shot of what does NOT work.

[Lovish]

Here, I have attached the screenshot after opening it again.
if every ping is working for you, can you check if you can ping 192.168.129.121- 126 to 192.129.168.133? it's still failing in the file I've already opened ( every other ping is working fine )

Edit: Alright so... I waited for like 10 mins, and every other ping is working fine, just like the file which is already open. Now, the only problem is the 192.168.129.133, which is not accepting any ping from any other PC.

[Joseph W. Doherty]

[Lovish]

Hmm... Let me try again, my new file is still open
Edit : so I have tried again, Now it works lol, I don't know how. 
Can you tell me how much time do we have to wait after opening the file? now that I have opened it for like 15 mins, it's working!

[Joseph W. Doherty]

Do you know the function of (bottom left)?:

If you click on the double arrow, it will bring all devices on-line and fully functional, very quickly.

[Lovish]

Oh, I see. I'm in my first semester, and I'm new to Cisco and Packet tracer, so I didn't really know this. But thank you so much for your help and for the solution as well. It really saved me today, lol. Thank you again.

[MichaelMcCoy]

No problem.  Good Luck in your studies!

[MichaelMcCoy · Accepted solution]

Hello Lovish,

So you will have to change your subnets. 

Use the following:
interface gi0/0

ip address 192.168.129.1 255.255.255.128

interface gi0/1

ip address 192.168.129.254 255.255.255.128

You were using the subnet mask of 255.255.255.0 that is not going to give you the two separate subnets that you need.  

Please mark this as the answer if it answers your question.

[Lovish]

Hi, Yes I have figured it out, and I was using the 255.255.255.128 but I didn't change the name on the PCs so that was my mistake, sorry about that but now I'm able to ping some of the PCs from upper part to the lower part, not all of them, I don't know why. and I will update the file on the post.