No ping response from NTP on 6850E

[bmccloskey]

This is an incredibly odd situation here. The network topology is as follows. At the core we have a 7750 at the remote site we have two 7210s, a stack of 3 6850E OmniSwitch Switches acting as a single switch. Those 3 switches are attached to the 7210s via a lag using fiber. From the 7750 there is another stack of 8 6850E switches and an NTP server is connected via the 8 stack. So from the 7210s, the 7750 and from the 8 stack of switches and all of the other switches in the network I can ping our ntp server. Now from the switches that are attached via a LAG to the 7210s i cannot ping the ntp server. I am able to ping the default gateway for the ntp server on the 7750 and from the ntp server i can ping the default gateway for the switches. But from the ntp server i cannot ping the switches themselves and from the switches i cannot ping the ntp server.

[frank]

Can PC behind the switches ping the NTP Server ?
From what I read, it can either be routing issue, or firewall, simply..

[bmccloskey]

Yes. PCs behind the switch are able to ping the NTP server. We are able to ping from other devices as well as other L3 and L2 switches on our network. We are currently working with ION support to resolve this issue. When a resolution comes around I will be sure to post it here.