Good evening,

Someone have any idea about what could be the reason I can't ping from one subnet to another in this scheme?
![enter image description here][1]


  [1]: https://i.sstatic.net/EFQkI.png

No ACL are defined in the 6509 and the sh ip route command displays both subnets as Directly connected.

I can ping IP addresses defined in the 6509: 172.20.X.2 and 172.20.Y.2 for example :

ping 172.20.X.2 source 172.20.Y.1 It works
 
ping 172.20.X.1 source 172.20.Y.1 It doesn't work.

PIM sparse-mode is enabled at 172.20.X.2.

Thanks in advance!