Issue with Packet Tracer Routes

[PrimeYeti]

This must be a super basic question, but if I have two routers configured with the below addresses, how can I get them to see each other?

R1 - Gi0/0/0 - 192.168.1.1/24 > R2 - Gi0/0/0 - 192.168.2.1/24

I'm currently using Packet Tracer and I can't add static routes in each router for the opposite subnet as they never appear since each address isn't reachable from the other. Seems like a bit of a paradox? Surely there is a way of doing it with static routes rather than OSPF or another routing protocol.

More out of curiosity than anything.

[David Ruess · Accepted solution]

Those networks are in different subnets. That's not a valid configuration.

Try this:

R1 - Gi0/0/0 - 192.168.1.1/24 > R2 - Gi0/0/0 - 192.168.1.2/24

The link connecting them must be in the same subnet. As you learn more about routing you will understand. In a sense if R1 thinks its one subnet and R2 thinks that same like is another subnet your routing will be messed up.

If you want to play around with static routes, either add more devices or add a loopback interface with an IP in a different network.

For example:

On R1 add the loopback 1, and on R2 create a static route to the loopback address of R1 using either the exit interface or next hop IP.

R1 - 

conf t

interface loopback 1

ip addresss 1.1.1.1 255.255.255.255

On R2

conf t

ip route 1.1.1.1 255.255.255.255 192.168.1.1

Hope that helps

-David

[PrimeYeti]

Hi David,

Thanks for the reply. In all honesty this was just me having a massive blonde moment. I know you should really have a subnet per link, VLAN, etc. I should know by now this wouldn’t work :’)

[Joseph W. Doherty]

Great, you understand why R1 - Gi0/0/0 - 192.168.1.1/24 > R2 - Gi0/0/0 - 192.168.2.1/24 doesn't work.

How about:

R1 - Gi0/0/0 - 192.168.1.1/23 > R2 - Gi0/0/0 - 192.168.2.1/23

or

R1 - Gi0/0/0 - 192.168.1.1/22 > R2 - Gi0/0/0 - 192.168.2.1/22?

Spoiler

The above /23 should also not work, but the /22 should.

or

R1 - Gi0/0/0 - 192.168.3.1/23 > R2 - Gi0/0/0 - 192.168.2.1/23

or

R1 - Gi0/0/0 - 192.168.3.1/22 > R2 - Gi0/0/0 - 192.168.2.1/22?

Spoiler

Both of these last two, /23 and /22, should work.

[PrimeYeti]

Hi Joseph,

Yeah I came to the same conclusion with these, thanks! As mentioned it was just me having a massive blonde moment. Funnily enough I was actually messing around with Loopback interfaces prior to this.

Thanks for the help!

[Joseph W. Doherty]

"As mentioned it was just me having a massive blonde moment."

Laugh, in my case it's "senior moments".