troubleshooting Question

Adding an additional Public IP Block on my Cisco 2801 Router

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denver218Flag for United States of America asked on
RoutersSwitches / HubsCisco
2 Comments1 Solution628 ViewsLast Modified:
I have a Cisco 2801 Router that connects me to the ISP.  This Router also does NAT/PAT, Firewall, VPN, etc.

As you can see below by looking at my interface configurations, I only have a /30 block of IP addresses.  We are getting an application on one of our servers that require a static NAT.  Since I don't have any IP addresses, my ISP just assigned me an additional block of IP's which is a /29 block.  So I have my WAN connection, which is a /30 block, and I have my public rout-able IP block which is a /29 block.  How do I configure my router for this additional IP Block?  Behind my 2801 router its a cisco 2950 switch.  The router is connected to the switch via interface FastEthernet0/0.  Should I add a secondary IP from the /29 block to interface FastEthernet0/3/0.1?  See interface configurations below:  Any assistance would be greatly appreciated.

interface FastEthernet0/3/0
 no ip address
 duplex auto
 speed auto
interface FastEthernet0/3/0.1
 description WAN_ISP
 encapsulation dot1Q 10
 ip address x.x.205.6
 ip nat outside
 no cdp enable
interface FastEthernet0/0
 description TO CISCO 2950 SWITCH LAN
 ip address
 ip nat inside
 ip virtual-reassembly
 speed auto
 no cdp enable
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