CCNA

A Network Technician configuring a router at Pass4Sure.com to provide internet access. The Pass4Sure ISP provided public IP address range of 198.18.32.65 - 198.18.32.70/29
(this is a C class IP, subnetting 5 bits in the host part, subnet mask is 255.255.255.248, block size is 8, IP range starts 198.18.32.0 – 198.18.32.7, 198.18.32.8 - 198.18.32.15 … 198.18.32.64 - 198.18.32.71 …)
ie, The ISP has provided six public IP addresses of 198.18.32.65 - 198.18.32.70

Pass4Sure.com has 62 clients that need to access internet simultaneously. This hosts use private IP address range of 192.168.6.65 – 192.168.6.126/26
(this is also a C class IP, subnetting 2 bits in the host part, subnet mask is 255.255.255.192, block size is 64, IP range starts 192.168.6.0 - 192.168.6.63, 192.168.6.64 - 192.168.6.127 …)
ie, The clients in Pass4Sure.com have been assigned private IP addresses of 192.168.6.65 – 192.168.6.126 Step: 1

Before starting NAT configuration verifies that router hostname is configured as Pass4Sure1. If not, change the hostname of the router to Pass4Sure1 using the command given below

Router>enable
Router#configure terminal
Router(config)#hostname Pass4Sure1

Step: 2

Configure appropriate interfaces for NAT Inside and NAT Outside statements. In this question configuration would have been like this

Pass4Sure1(config)#interface fastethernet 0/0
Pass4Sure1(config-if)#ip nat inside
Pass4Sure1(config-if)#exit
Pass4Sure1(config)#interface serial 0/0
Pass4Sure1(config-if)#ip nat outside
Pass4Sure1(config-if)#exit

Step: 3

Create an access-list to match the address range of clients in Pass4Sure.com for NAT translations

Pass4Sure1(config)#access-list 10 permit 192.168.6.64 0.0.0.63

Step: 4

Create a NAT Pool with pool name isp_adr and specify the pool address range provided by ISP with their netmask.

Pass4Sure1(config)#ip nat pool isp_adr 198.18.32.65 198.18.32.70 netmask 255.255.255.248

Step: 5

Using the command ‘overload’ to specify Port based NAT to support all the address range of clients in Pass4Sure.com

Pass4Sure1(config)#ip nat inside source list 10 pool isp_adr overload

Step: 6

To save this configuration

Pass4Sure1(config)#end
Pass4Sure1#copy run start

N.B: IP addresses in this question are may be changeable Sphere: Related Content