double nat translation

Maxim Kursin · ‎01-14-2009

hi all!

help to understand the following issues:

for packet, that entering the router (cisco 2811) must be changed source and destination address. for example on the interface fa0/0 hits packet with the source address 10.10.10.1 and the destination address 192.168.240.1, and at the exit from the router (fa0/1), I need to have a packet with the source address of 192.168.4.4 and destination addresses 192.168.4.1

192.168.4.1 - host, which could take the packages from its subnet (192.168.4.0/24)

10.10.10.1 - can apply only to hosts on the network 192.168.240.0/24

P.S. sorry for my english

andrew.prince · ‎01-15-2009

If the router has 2 x interfaces:-

fa0/0 connected to the subnet 10.10.10.0/24

and

fa 0/1 connexted to the subnet 192.168.240.0/24

AFAIK you cannot double NAT to an IP range, that is not directly connected to the device.

Maxim Kursin · ‎01-15-2009

I have attached a simplified scheme, I hope this helps ...

Maxim Kursin · ‎01-15-2009

Also, I have found here a similar topic (http://forums.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Network%20Infrastructure&topic=LAN%2C%20Switching%20and%20Routing&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40^1%40%40.2cc2a432), but I have ip nat inside and ip nat outside vice versa. I can not change thish because on both interfaces, there are already some translations

andrew.prince · ‎01-15-2009

you diagram does not show where the 192.168.240.0/24 is?

Maxim Kursin · ‎01-15-2009

there is no it. our border router route packet on cisco 2811 to fa 0/0 (172.16.1.1). if needed, i may on interface fa 0/0 create a subinterface with 192.168.240.1 ip