I spent three pc path simulation machines were r1, r2, r3, r1 and 1900 switches connected together and then to 3550 and the remaining two directly linked to 3,550 in 3550 divided the vlan:vlan1, vlan2, vlan3 and made routing. R1 is vlan1 other analogy. In 1900 and 3550 linked to the use of anti-ray, while the others are contrary. On the question : r1 of ping r3 nowhere, but has no ip routing through. Ip routing Why nowhere?
I also learn routing configuration, Bangniding! If you do not use the no ip routing r1 Routing devices will find the path to the destination, without routing configuration, the router does not know what data will be transmitted away from the port which will Loss