STATIC NAT

[gcocchi]

I'm trying to configure static nat in this way:

fa0/0 - 192.103.83.100 - nat outside

fa0/1 - 192.168.40.254 - nat inside

I need to access ip 192.168.40.100 from outside to inside using a different ip address, so i configured

ip nat inside source static 192.168.40.100 128.20.0.100

The clients on outside network are connected with normal layer 2 switch.

If i ping 128.20.0.100 the cisco router does not reply to my arp request, but if i configure for static nat an ip on 192.103.83.0 subnet, it works correctly.

If i configure the ip address 128.20.0.100 as a secondary ip on outside interface fa0/0, nat start working.

There is a method to configure 128.20.0.100 without setting secondary ip address?

Reading the docs i noticed that setting up static nat 1:1 is equivalent to setup an ip alias, but using a different subnet this does not work.

Thx.

[ehirsel]

What is the ip address of the client off of the outside interface? What acl's do you have applied on the outside interface?

When you did your 1st attempt: no secondary ip address, global nat is 128.20.0.100, was the client configured to use the fa0/0 192.103.83.100 address as the gateway to 128.20.0.100?

[tekha]

Have you tried making a ip route for the host ip 128.20.0.100, going out fast 0/1?

ip route 128.20.0.100 255.255.255.255 FastEthernet0/1