I just purchased a new ASA5510 to replace our old firewall. With help from experts in the forum, the device is configured to have an inside, outside and dmz interfaces. Now here's my question, how should/do i subnet my IP block?
My ISP has given me a block of IPs x.x.x.32/27. In my current setup the ISP gateway is x.x.x.33/27, my old firewall gateway is on x.x.x.34/27, two VPN gateways on x.x.x.37 and x.x.x.40/27. My three gateways are running parallel. I have 2 machines setup with one to one nat to provide web services on x.x.x.35/27 and x.x.x.36/27. I have a DMZ setup with x.x.x.55/27 to x.x.x.62/27.
I was thinking having the first x.x.x.32/29 block for the devices running parallel to the new firewall. The second x.x.x.40/29 block for my outside interface (and one to one NATs) and the last block of x.x.x.48/28 for my DMZ interface. Does this sound ok?
If I proceed with the config, what IPs would I assign to the devices running in parallel? For example, if i choose to give the x.x.x.35 ip to my VPN gateway, would I assign it x.x.x.35/27 or x.x.x.35/29 IP?
Thanks for your reply.