Hi,
RIP, routing information protocol tells routers what other routers can reach.
Case 1: So lapA is assumed to have a default gateway set at Router1, that will 
be the first stop of the ICMP echo. Then Router1 sees that the destination is a 
directly coupled interface, Router2, so it passed the ICMP echo there.
Now Router2 may have a problem finding it's way back to the network on which 
lapA sits, since Router1 doesn't tell that it has that network. If Router2 has a 
default route through Router1 everything may end well.
Case 2: Now if Router2 is listening for RIP it should know how to find its way 
back to lapA, namely through Router1.
It has been a while since I played with this stuff, so I may have left something 
out.
Thanx,
Jaap
PS: netkit is an ideal tool to play around with these kind of things.
jose john wrote:
Hi There,
     Suppose I have a network like lapA-----Router1-----Ruoter2. Both R1 
and R2 have the RIP disabled.
 Case1: What will happen if I ping R2 from lapA
 Case2. What will happen if the RIP is enabled on R1 and am trying to 
ping R2 from lapA?
 
Thanks,
Jose John