Enable networking for two Linux machines to see each other
 

So I have two Linux machines that are on two different subnets:

machine 1 - 192.168.254.132 gateway - 192.168.254.64

machine 2 - 193.168.220.232 gateway - 192.168.220.1

I am not able to ping either one of these machines and I've checked to see if routing is on and its not.

Do I have to turn on routing in order for these machines to ping each other as well as create some sort of iptables rule too?

Let me know if we need more information.

maybe a silly question but why have two different subnets? why not just put them on the same one?

Subnet mask would tell us something I'd think.

The basic part of your question is the use of ping. Without knowing if ping is enabled we also can't say. Generally ping is a poor choice to use as it is being more and more blocked.

Also, can we assume the gateways know routes to each others set of ip addresses?

One is in a DMZ, therefore in a different subnet.

The one server that isn't in the DMZ has a subnet mask of 255.255.252.0

The server in the DMZ has a subet of 255.255.255.0.