netkit: why cant my router 4 pc4 ping my router 1 pc1 - how can I solve this please?

Question

Below I have four routers connected but my pc1 on r1 cannot ping my pc4 on r4 and also my pc2 on r2 cant ping my pc4 on r4 and vice versa. Below is a network diagram: and the configurations are below that, could anyone help me please on making them accessible?

![connecting 4 routers][1] I cant post my diagram on serverfault(less than 10 rep) so I did on stackoverflow and asked the same question.

pc1:

ifconfig eth0 195.11.14.5 netmask 255.255.255.0 broadcast 195.11.14.255 up
route add default gw 195.11.14.1 dev eth0

pc2.start:

ifconfig eth0 200.1.1.7 netmask 255.255.255.0 broadcast 200.1.1.255 up
route add default gw 200.1.1.1 dev eth0

pc3:

ifconfig eth0 195.20.14.9 netmask 255.255.255.0 broadcast 195.20.1.255 up
route add default gw 195.20.14.1 dev eth0

pc4:

ifconfig eth0 200.2.1.11 netmask 255.255.255.0 broadcast 200.2.1.255 up
route add default gw 200.2.1.1 dev eth0

r1:

ifconfig eth0 195.11.14.1 netmask 255.255.255.0 broadcast 195.11.14.255 up
ifconfig eth1 100.0.0.9 netmask 255.255.255.252 broadcast 100.0.0.11 up
route add -net 200.1.1.0 netmask 255.255.255.0 gw 100.0.0.10 dev eth1
route add default gw 100.0.0.10

lab.conf: if you need more on that Ill post it up but I think most of the info is there. Any help would be greatly appreciated especially trying to make a connection between pc4 and pc1, even if you think it does not make sense please explain why. Thank you.

Answer 1

Having drawn a picture myself, I think the issue is that router 4 has no dedicated route to 195.11.14.0/24 (which is the network that PC1 is on), and it has three default gateways, one of which is itself (200.2.1.1), one of which is not directly attached and therefore illegal (100.1.1.9), and one of which is right (110.2.2.9).

If you get rid of the two wrong default routes on router 4, and none of the routers has any kind of firewalling or access-control, the packets should flow.