cannot ping the other side of router

[pate...@gmail.com]

I have configures this network.
I have enabled the packet forwarding in linux router.
when I ping from pc1 to pc2 everything works fine. the same the other way
when I ping from pc1 to linux1 i get response. the same from pc2.
Also when I ping from pc1 to the other side of the linux1 I get responce.
But I can't get responce when I'm trying from pc2.
Also when I ping the notebook0 from pc1 I can see the yellow packages reaching notebook0 but it doesn't respond.
when I do the same from pc2 I just get network unreachable (without sending any packages).

[pate...@gmail.com]

turns out I haven't configured the network properly (haven't set static routes and default routes). For a nice tutorial I have found http://www.brianlinkletter.com/psimulator2-graphical-network-simulator/#more-1778