I'm having a issue with receiving duplicate packets in my network and I'm unsure what's causing it. A simplistic explanation of what's happening is this:
Server1 sends a ping request to Server2
Server2 receives the ping request from Server1, sends ping reply to Server1
Server1 receives two ping replies (DUP)
The network layout is pretty simple - here is a (poorly) drawn diagram:
Some things to note that I think is related:
The SW1.LAX.AGG switches each have RVI's from different subnets. We have a VLAN called "test" with subnets 10.0.0.0/24, 10.0.1.0/24 and 10.0.2.0/24. The VLAN interface has the first IP of each range assigned. The VLAN "test" has a "l3-interface" pointing to the proper VLAN interface.
When you ping an IP from another subnet (say pinging 10.0.1.200 while the primary IP on the machine is 10.0.0.200) it goes over the default gateway of 10.0.0.1 and gets the DUP ping reply. When pinging from a secondary IP on another subnet (10.0.2.200) using the
ping -i eth1:0there is no DUP reply.
When receiving the duplicate reply the TTL is not increasing or decreasing.
This is not a duplicate IP issue.
Any suggestion on how I can debug this further / is there something silly I'm missing?