How to set one to one NAT ?

[Wilson Kwok]

Hello,

Please see attached screenshot first.

Internal have 2 servers for public users, how to map one to one NAT to those internal IP on Router 5 fa0/1 ? assume public IP has 210.0.214.1 - 3.

I tried to create subinterface on Router 5 fa0/1, assign encapsulation dot1Q 1, assign 210.0.214.2 on fa0/1.1, it has error message overlap on fa0/0 internface...

Thanks !

[ebarticel]

Hi Wilson,

You need to enable interfaces for nat first (ip nat inside(default gateway for servers), ip nat outside)

Second you need to add a secondary ip address to interface that connects to other router (ip address 210.0.214.3 255.255.255.0 secondary)

Third, you need to create a static mapping from each server IP to the default gateway (ip nat inside source static 192.168.0.2 192.168.0.1)

And router should take care of the rest.

I hope this helps

Eugen

[Wilson Kwok]

Hi,

Do you mean enable sub-interface for 210.0.214.3 ?

I known nat need define inside and outside.

[ebarticel]

You dont need subinterfaces, on the physical interface you can assign a primary address 210.0.214.1 and a secondary 210.0.214.3 for example.

Another way is to create a pool of addresses from 210.0.214.0 subnet and an ACL to permit both servers to use the pool for translation.

Check this link

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_q_and_a_item09186a00800e523b.shtml

Eugen

[Wilson Kwok]

Packet Tracer do not support secondary ip address ... I tried real 2600 router can assign secondary ip address.

Thanks !!

[Kodandarao.Allipilli]

Hi Wilson,

Pls find below suggested config...as per your 03.jpg

configure for R5

Router#configure terminal

R5(config)#interface fastethernet 0/0

R5(config-if)#ip address 192.168.0.1 255.255.255.0

R5(config-if)#no shutdown

R5(config-if)#ip nat inside

R5(config-if)#exit

R5(config)#interface fastethernet 0/1

R5(config-if)#ip address 210.0.214.1 255.255.255.0

R5(config-if)#no shutdown

R5(config-if)#ip nat outside

R5(config-if)#exit

R5(config)#ip route 210.0.214.0 255.255.255.0 192.168.0.0

R5(config)#ip nat inside source static 192.168.0.3 210.0.214.3

configure for R6

R6(config)#interface fastethernet 0/0

R6(config-if)#ip address 210.0.214.2 255.255.255.0

R6(config-if)#clock rate 64000

R6(config-if)#bandwidth 64

R6(config-if)#no shutdown

R6(config-if)#exit

R6(config)#ip route 210.0.214.0 255.255.255.0 210.0.214.1

R6(config)#

Regards,

KodandaRao - Please rate helpful posts