real and private ip's

[amrqura]

hi all,

i'm new employer in my company and when i browse the network and see the router configuration i see the following:

interface

interface FastEthernet0/0
ip address 192.168.1.7 255.255.255.0
ip address 172.16.x.x 255.255.255.252
ip nat inside

my question is :


why the interface have two ip's.

as i know that ine of them is for private ip and the other is public ip ...... why it's not assigned only the private IP and the nat process male the conversion.

 

[burtsbees]

Both of those addresses are private IP addresses---neither are public. One of them is probably left over from a previous configuration, and was never taken off, or it may be used as a secondary IP address, but the keyword "secondary" is missing.
One of them is meant to be converted to a public IP address (with "ip nat inside"), but I cannot be sure which...what private pool does the rest of the LAN connected to fa0/0 use? One of those should be removed, if it is not being used...

Burt

 

[DanInRaleigh]

.does one of those IP addresses have secondary beside it. like secondary IP address.

At my compnay (large ISP) these secondary IP addresses gives us the ability to manage the interface by another IP address...doesnt matter to much if public or private.. could be for a couple of reasons....one maybe the firewall is blocking specific ranges..

...and obviously the secondary ip is being advertised in bgp as normal...

http://www.daniel-white.com