ARP Table Updating

Good morning,

I have a Dell 6248P/6248 Switch stack with 9 switches. I am actually learning as I go about routing and switching so please bear with me on my question.

We are in the process of putting VLAN's in and the individual that was helping out did a lot of things on his own and did not document everything. His access was removed by my boss so we can see exactly what has been done and why.

One of the VLAN's in question is the new VLAN 11 voice VLAN. We have moved 20 test users to this VLAN and are experiencing issues. When users in the regular VLAN from the flat network call users in the test VLAN 11 sometimes the call works perfectly and sometimes you can't hear one or the other. I did some reading and believe the ARP cache may not be working properly on the switches. Oh, I forgot to add we are using the switch stack to do the routing as they are layer 2/3 switches.

While investigating the ARP settings I found they were set to 6 hours. I chose to use the recommended 4 hours that Cisco uses. While watching the ARP table I am see the aging constantly resetting and none of them aging much more than 30 seconds. Is this normal for the ARP table to update that often?

Thanks in advance