How to Tee udp packets onto a different host
I'm running some instances in Amazon's Virtual Private Cloud. One instance is inside a VPN only subnet (10.128.1.0/24) connected to a corporate network (172.16.32.0/24). I have no control over anything on the other end of the tunnel. I only control what's going on in the VPC.
There is a physical server that is sending UDP packets through the tunnel at a proxy server I'm trying to setup through iptables. I'm going to have several app servers in different environments that all need to receive these UDP packets (in the 10.128.5.0/24 subnet). My first attempt at setting up iptables was:
iptables -t nat -A PREROUTING -s 172.16.32.0/24 -p udp --dport 1360 -j DNAT --to 10.128.5.10:1360 --to 10.128.5.11:1360
The problem is two fold. First iptables no longer supports multiple
--to flags. And secondly, from my understanding it would have round-robin'd the destination but I need the UDP packets to go to both destinations simultaneously.
QUESTION: Given my constraints, how do I receive a UDP packet and send it simultaneously to two different destinations? I would prefer to keep it in iptables if possible.
EDIT (for clarification): I have UDP packets coming into the proxy (server A). I want that packet to be received by two other servers (B & C), and possibly others in the future. Source address of the UDP packets received by B & C is of no concern, and B & C will never need to send any kind of response back. This is strictly one way. Is this possible and if so how?