I'm still trying to wrap my mind around subnetting and was hoping somebody here could point me in the right direction. I am setting up a mail server and hardware firewall (Sonicwall) behind a DSL router. The ISP has given me a "/29" subnet which should have 6 usable IP addresses. They gave me the following information about these IP's (I've hidden the first 3 blocks for privacy):
x.x.x.32 = Subnet
x.x.x.33-39 = Usable IP's
x.x.x.40 = Broadcast
I want the firewall to have it's own WAN IP (.33 perhaps?) that is seperate from the DSL router's WAN IP.
I have another site that is already configured with this setup and was planning on copying their configuration but I wanted to understand exactly what I'm doing. At this other site, they have the DSL router's WAN subnet mask set to 255.255.255.248 and the LAN subnet mask set to 255.255.255.252. They also have the WAN subnet mask on the firewall set to 255.255.255.248 with it's own WAN IP. Can anybody explain how all of this works or point me to a good link? Thanks!