Vlan and router on stick with more than 2 router.

[Romuald Tiwa]

Switch1R1R2

R3

P3,P2 on vlan 10 and PC W10 on vlan 20 can ping  interface e0/0 (168.0.0.1) on R2 but cannot ping interface e0/0 (168.0.0.2) on R3. I configured OSPF protocol on all routers.

 I would like to connect vlan 10 to vlan 10 and vlan 20 to vlan 20 on differend networks.

Please can anyone help me to solve it.

Thank you.  

[MHM Cisco World]

friend you can not split L2 subnet by L3 router 
here you split 10.0.0.0 by three routers and this not work 
you need to config different subnet in each R1 and R3
or make L2VPN (this hard and can not run in gns3 lab)
MHM

[Romuald Tiwa]

Okay, Thank you, I assigned different IP addresses to each subnetwork and the ping works very well. But now the problem is that a PC from one subnet pings all the PCs from another subnet regardless of whether they are in the same vlan or not. on the other hand respects the conditions in its own subnetworks, that is to say in its subnetwork it can only ping the PCs which belong to its vlan which is normal. I'm a little confused.

[MHM Cisco World]

same vlan 
the vlan tag is locally in router 

so you can use vlan 10 with subnet 10.0.0.0/24 in router 1
and use vlan 10 with subnet 100.0.0.0/24 in router 2 
the host in vlan 10 connect to both router can connect to each other

MHM

[paul driver]

Hello

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@Romuald Tiwa wrote:
 I would like to connect vlan 10 to vlan 10 and vlan 20 to vlan 20 on differend networks.

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This will not be applicable, you cannot extended the L2 vlan with this topology, the 10.x.x.x subnet needs to reside on just the one network, the only way this is possible is to incorporate some NAT to "hide" one of the 10.x.x.x networks or to re-address one of them

[Romuald Tiwa]

Okay, Thank you, I assigned different IP addresses to each subnetwork and the ping works very well. But now the problem is that a PC from one subnet pings all the PCs from another subnet regardless of whether they are in the same vlan or not. on the other hand respects the conditions in its own subnetworks, that is to say in its subnetwork it can only ping the PCs which belong to its vlan which is normal. I'm a little confused.

[paul driver]

Hello

@Romuald Tiwa wrote:

Okay, Thank you, I assigned different IP addresses to each subnetwork and the ping works very well. But now the problem is that a PC from one subnet pings all the PCs from another subnet regardless of whether they are in the same vlan or not. on the other hand respects the conditions in its own subnetworks, that is to say in its subnetwork it can only ping the PCs which belong to its vlan which is normal. I'm a little confused.

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What is it you are confused about?
Most devices in a network should be reachable to one another unless you wish for that not to be or a security policy states so.
A host that is reachable not only in its own vlan but to other hosts in other vlans is due to inter-vlan routing performed by a routing device such as a Router/Firewall/L3 switch.