Changing an IP address on a 2600 Cisco router 1

[tpk613]

I am setting up a firewall and have two questions about my 2600 Cisco router. Currently I have the ethernet port set to a private Ip adress and want to change it to a public adress so I can communicate with my firewall that has a public Ip on it's WAN port. What is the syntax to change my current setup on the Ethernet port and 2, Just to be sure I don't lose my current configuration. Is there a way to save off my settings. (I beleive if I don't write the changes to memory at the end of my changes, when I reboot it should go back to the way it was before the changes.) Any help is appreciated. Thanks! One more thing is there a Rem statement I can use? Config I want to change looks like:
!
interface FastEthernet 0/0
ip adress 33.0.2.34 255.255.0.0
no ip derect3ed-broadcast
ip nat inside
!
(interface serial 0/0 here)
description yadayadayada
bandwidth 1544
ip adress 132.xxx.xxxx 255.255.255.xxx
no ip directed broadcast
ip nat outsides
no ip mroute-cache
!
NAT pool etc. below

 

[kcbell]

To change the IP of an interface, you must know the enable password. If you enter the enable password, you do the following:

conf t
inter s0/0 <assume s0/0 is the interface that you want to change the IP>
ip address 12.123.123.123 255.255.255.255
CTL Z to get out of config mode

You could do a
show run
to see the change.

Yes, if you don't do the
copy run start
The configuration will be back to the original. However, before you do the ip change you may want to be sure to save the config before changing the IP by doing a
copy run start

Hope this help!

 

[tpk613]

I am familiar with conf t and some of the basic commands. The Ip I want to change is on the FastEthernet side so I guess i will use the same syntax? And Do IO need to do anything about that No ip detected broadcast, or the inside NAT statement? Because this is the port I need to change to the Public Ip? Thanks for your assistance.

 

[kcbell]

The only thing you need to change is the IP address. The interface would be &quot;inter f0/0&quot; for FasteEthernet 0/0. You also need to know the network mask of the IP range that your ISP is providing to you.

Have fun!

 

[tpk613]

Seems easy enough. So that inside nat statement doesn't matter that it's there? Also, you are probably familiar with this list but as you can see the first access list permitisfor my private ip scheme does that need to be changed for the public to work or am I okay since everything will be on the public scheme now? (config below) to save the config do I need to be in conf t mode and where does it save to do I get prompted? Thanks for your help you have been great!! (config below)
!
access-list 1 permit 33.0.0 0. 0.0.255.255
access-list 10 permit 155.xx.xx.xxx 0.0.0.41
snmp server engineId 00000xxxx
snmp-server community bawave RO 10

 

[kcbell]

tpk613:

>>>>>Router>>>>>>>>>Firewall>>>>>>>>>>>Computers
PublicIP PrivateIP1 PrivateIP2 Private IP3 PrivateIP4..254

First of all, I am still learning Cisco stuff. I think the diagram above is what you want to do.

To save the configuration, the command is &quot;copy run start&quot;. It means copy the run configuration to the flash memory. It will ask you the file name. You can enter whatever you want. When the router is boot up, the file that it will load from is the start-config file.

For PrivateIP1 & PriiateIP2, you can use 10.10.1.1/24
For PrivateIP3 & all other IP can be assign by the admin, you can use 10.10.2.1/24.

The range is an example. Hope I am right...Someone more exprience than me, please confirm!

 

[tpk613]

My experience with some of the commands are a little new but it seems pretty simple. There isn't any more private IP scheme everything on the outside of my firwall, including the DMZ is public ip's that is why I am changing them. Thank you for your help though you did get me in the right direction. Good luck with the Cisco stuff!