Network Addressing Error Routing Ping Timeout

[cassidykerrie]

Hello Community,

I am in the beginning stages of studying Network Technologies. I am trying to ping between two simple subnetworks but the request times out when I try and ping from one side of the network to the other sides router. I have watched countless, countless hours of content to try and fix whatever error I am making but I am completely lost. To the best of my knowledge I have confiIf someone could review my subnet logic I would greatly appreciate it. I know it's probably a simple error but I have lost hope in figuring it out myself. 

Many thanks in advance for your time and help. 

[David Ruess]

Hello,

If I understand your picture correct you have 1 network as 178.3.34.128/25 and you are trying to break that into 2 separate networks (subnet) to accommodate each router interface and LAN subnet where the PCs reside?

If that's correct can you provide the router output. You did not provide any subnet mask info for the PCs or the router interfaces. Since you subnetted you need to make sure everything is a /26 since you are breaking the /26 into 2 subnets. Also make sure the router interfaces are turned on (no shut).

Side note, can any device ping their default GW (router interfaces)? If not then there could be something on the L2 switches preventing communication.

-David

[cassidykerrie]

Hi David,

Thank you so much for your prompt response. It is part of a lab that I have to do for college. We were assigned the IP address 178.3.34.128/25 and we have to break that down into subnets, with 60 subnets per host. 

Does this information change your solution? I thought that because the assigned CIDR notation was /25 that I wouldn't have been able to change that. If that's the solution I feel very silly! I have spent hours checking my logic trying to get this working. 

My router's are on - that was something I learned the hard way at an earlier point in the assignment!

I have the same subnet mask for every PC and router. How do I provide router output? Apologies for the noobiness

All devices can ping in their individual subnets, just not across subnets. 

I have attached the zip file if that helps

Thanks so much for your time and energy,

Kerrie. 

[David Ruess · Accepted solution]

Change your default GW on your PCs. The DG is 1 IP off. It needs to be the IP address of the router interface they will hit first to get out of their subnet. 

For example:

PC-A3s default gateway was 178.3.34.128 and it needs to be the IP of G0/01 of 178.3.34.129. DO the same for the other side and G0/1. The DG of the PCs should be .193 for the other side. I changed that and was able to ping.

-David

[cassidykerrie]

Hi David,

I cannot thank you enough for sharing this information with me. I can't believe it was such a simple fix! 

So in future, when setting up networks, am I correct in saying that the default gateway of any devices is the same as the IP of whatever router is routing them, and that the subnet ip is not an ip that is used in configuration of network devices?

Many thanks,

Kerrie.