Router connection problem

I have a problem regarding routers. Below is my diagram

I have 3 routers. My base network is 192.168.1.0 and im using this network to subnet into VLSM and i already created 3 LANs. [LAN 1, LAN 2, LAN 3]

Is it the routers connection must use same subnet or can be different?? I couldn't ping host from router 0 to host in router 2. But i can ping host from router 0 to host router 1.

When i ping it shows "destination host unreachable"

What could it be the issue? I confident that i assign correct IP.
Is it the routers connection must be under same subnets or can be diffrerent?

The image is not so clear. If you could post your packet tracer .pkt file it would be much easier to look into it.

Hi, finally i can ping to all hosts from any LAN!!
Below is my diagram. However i have one doubt. Why I cannot use /30 subnets for all my router serial connections??
[I mean only for router serial conn part]

That's the problem that make me unable to connect to all host. The problem have been solved by changed to /29 subnets for all router serial connections. Why is like that?

www.savefile.com/files/1571362

When I set the masks to /30 it works!!. From which to which were you pinging?

fixed file is here: www.downloadtaxi.com/d/1211718283

Hi, First of all thank u very very much for your kind help!!!

Well, my previous configuration as below:

Router 0
s0/0 192.168.1.81/30
s0/1 192.168.1.86/30

Router 1
s0/0 192.168.1.82/30
s0/1 192.168.1.89/30

Router 2
s0/0 192.168.1.90/30
s0/1 192.168.1.85/30


**The serial connection between Router 0 [s0/0] and
Router 1[s0/0] works fine and can ping with that LAN networks.

**But other connection wont works for me.

Can u help me to clarify this?

Thanks.

Router 2 configuration is flipped. It should be like this:

Router 2
s0/1 192.168.1.90/30
s0/0 192.168.1.85/30