I have setup NAT for a wireless network. I’m using a /21 as private address space and four (4) external IPs. It works, but there is a problem:
The NAT mechanism uses all 4 external IPs (as it should) for the translation and load balances the translations per flow. This means that you can see different flows from one internal IP to be NATed to different external IPs.
10.5.10.196 x.y.61.84 tcp 271870
10.5.10.196 x.y.61.85 tcp 260527
10.5.10.196 x.y.61.84 tcp 248671
10.5.10.196 x.y.61.86 tcp 269582
10.5.10.196 x.y.61.85 tcp 244858
That makes a few applications to break.
Can I do still use the four external IPs and load balance the NAT by internal IP? This way, each internal IP would use a specific one external IP at any one time.
Can I do this?