I have a cisco firewall with a /30 internet connection. There is an outside interface and an inside interface connecting to a switch where clients sit in..
All clients coming from the internal network are patted to the outside interface in order to reach the internet.
I now have a server on the internal network that i need to access form the internet. Is it true that i cannot make a static nat statement and pat into this server on port 443 using the ip-adress of the outside interface? Do i really need a /29 and more ip-adresses in order to accomplish this? If no how would i go about natting to my server? Everytime i attempt to nat asdm tells me that my nat statement would overlap with the outside interface.
I assume that your ASA is running with pre 8.3 IOS version...
It is similar to configuring global nat using IP in ASA where we cannot use single IP to configure multiple global nat statements and we cannot use single IP to configure multiple combinations of NAT statement..
Same applies for interface NAT also..
So you need one more IP to use for inbound connection to internal server's
You can try this for better utilization of IP's:
Since it is /30 and you are configuring in your firewall outside interface directly, I assume that you are not using any dynamic protocols for subnet advertisement or receival.
So you can ask service provider to configure private IP's for LAN connectivity and utilize the full /30 only to do NAT (since it is assigned to interface now, you cannot use its broadcast & unicast IP. So if you release those public IP from interface assignment, you can utilize complete /30 - 4 IP's to do NAT.. In Juniper firewall broadcast and unicast IP's can be used to do NAT by enabling point to point option though you assign /30 to interface)
I have not used ASDM, but in my experience setting up a static NAT/PAT is no problem at all. Some router software can be a pain with weird or over-simplified setups for this. But I'm assuming ASDM is better than that.