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New Member

aliasing ip's


I was wondering if it's possible on a 1720 to alias an ip on the serial

interface, so that I'd have 2 public ip's, 1 ip for each domain behind the


------------ | |

internal nic | | |cisco | 101.x.x.1

-------------| FW-1 | outside nic e0/0 |7000 |-------s0/1----|

| |------>---------------- | |: |----------t1

------------ | |-------- s0/7---|

101.x.x.2 - aliased ip

101.x.x.1 would be directed to via the firewall

101.x.x.2 would be directed to via the firewall

So that the webpages, and email could be hosted on 2 separate machines.


Cisco Employee

Re: aliasing ip's

your diagram was all messed up because of html conversion.

You should be able to do this with nat.

create a static nat like this :

ip nat inside source static tcp x.x.x.x 80 p.p.p.p 80

ip nat inside source stattic tcp y.y.y.y 25 p.p.p.p 25

p.p.p.p is your public address which will be translated to 2 different addresses.

x.x.x.x for web traffic and y.y.y.y for email traffic.

This could also be done on the firewall I believe.

New Member

Re: aliasing ip's

that would give me 2 different servers 1 for email, 1 for web...I want 2 different domains. each domain has it's own web, and has web, and email services on this server has web and email services on this other server

I want each domain to have it's own public ip, so is it possible to alias a second ip on the serial interface?