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

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!

  • 2
    Are you pinging from Windows devices with firewall enabled?
    – Ron Trunk
    May 18, 2015 at 16:53
  • 2
    Your problem exists on the devices at the other end of the routed link. What do you have configured to tell those devices to look to the 6509 for other networks? Are they Layer-3 switches? Those would need static or dynamic routes. PCs would need the firewall disabled to ping. You don't provide enough detail to answer the question.
    – Ron Maupin
    May 18, 2015 at 16:59
  • No, one is a Server with Default GW is 172.20.X.2 and other is another server with default GW 172.20.Y.2. No windows nor firewall, but Debian without iptables. Probably the problem is at the end devices but don't know what could be the reason yet. I keep looking for it.
    – RS1983
    May 18, 2015 at 17:05
  • 1
    Subnet masks on remote machines?
    – Robert
    May 18, 2015 at 19:10
  • 1
    Can you ping both servers from the 6500?
    – YLearn
    May 19, 2015 at 2:13

1 Answer 1


As I wrote in my comment, the problem is at the remote (from the 6509) end of one or both links.

Based on your comment, this appears to have been the case (application problem).

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