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can IP address be given to CISCO Router CISCO Firewall and Mail server from the same IP address pool

I am asking this question because the vendor supporting our CISCO Router & CISCO Firewall (ASA) is telling me that this can not be done and we should have one more IP pool
Ramesh Satija
Ramesh Satija
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Dr. KlahnPrincipal Software EngineerCommented:
Are you asking about the outward-facing IP or the inward-facing (LAN) IP?
As a general rule, you can't have the same ip pool, specifically a subnet, assigned to two different interfaces on the same device. So an ASA can't have the inside and outside interfaces configured with because they overlap.
So if you have Internet-ASA-Router-LAN, every spot between devices needs to be a different subnet or it will cause either a routing issue or it plainly won't be allowed on a device.
Now to go off of what Dr. Klahn was getting at, if you want to use a single Public IP address pool, and assign individual IP's to go to other devices behind the firewall, that is a simple matter of configuring NAT.
Ramesh SatijaAuthor Commented:
Thaks both of you for further comments / info. To answer Dr Klahn' query on my question, I am talking about outward Ip as well as inward -facing (LAN) IP, because all our ISP has given us one public IP Pool of 16 IP addresses, and no additional public ip for outward or WAN IP.

However after reading the detailed comments / suggestions of Mr rauenpc, I will discuss with my CISCO support vendor and then give further comment

Thanks to both of you for help
Dr. KlahnPrincipal Software EngineerCommented:
System requested close
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