NAT with secondary IP

[Miguel Angel Fernandez-Nieto Gomez]

Hello guys!

I have some troubles doing NAT. If I set up NAT for a particular port, the server replies, but it does so from a different IP address, (specifically from the main IP).

If I set up NAT to B.B.B.B, the NAT inside works, but replies from A.A.A.A.

What you think that it is due?

/***** THIS IS MY CONFIGURATION ** \

interface GigabitEthernet0/0

 description $ETH-WAN$

 ip address A.A.A.A 255.255.255.0

 ip address B.B.B.B 255.255.255.0 secondary

 ip access-group ACL_IN in

 ip nat outside

 ip virtual-reassembly in

 duplex auto

 speed auto

 no mop enabled

 crypto map SDM_CMAP_1

!

ip nat inside source route-map SDM_RMAP_1 interface GigabitEthernet0/0 overload

ip nat inside source static udp 192.168.10.70 5060 B.B.B.B 5060 route-map NONAT extendable

ip nat inside source static tcp 192.168.10.70 22 B.B.B.B 22 route-map NONAT extendable

ip route 0.0.0.0 0.0.0.0 C.C.C.C

ip access-list extended ACL_IN

......

 .....

!

route-map NONAT permit 11

 match ip address 115

!

[sushanth.shetty]

If I set up NAT for a particular port, the server replies, but it does so from a different IP address, (specifically from the main IP).
What is your network topology? Are you trying to reach the server from another site or internet?

Secondary IP address command on the router is used to bind another(second) subnet to the same interface.  Ex: On a multi-home setup or during migration from on address scheme to another (say 192.168.1.0/24 to 10.10.1.0/24)

Is this a multi-home setup?