Solved: Are these two "ip nat" statements equivalent

thomasdzubin · ‎12-01-2008

I manage a bunch of routers... on some, the outside-to-inside port address translation statements are set up like this:

ip nat inside source static tcp 192.168.10.69 25 24.56.67.89 25 extendable

(24.56.67.89 is my outside public IP assigned to FastE4)

while other routers are set up like this:

ip nat inside source static tcp 192.168.10.69 25 interface FastEthernet4 25

Both ways work fine, although I prefer the latter way in case FastEthernet4's IP address changes. Are there any real significant difference or are they really just the same?

Jon Marshall · ‎12-01-2008

Thomas

Not aware of any significant difference. They achieve the same thing.

Jon

View solution in original post

satish_zanjurne · ‎12-01-2008

Yes !!

1.You are right , it is used in case IP Address of NAT interface change , you don't have to change that address in NAT statement

2.Other important thing is , in case you are using DHCP to acquire IP address for Fastethernet interface ( i.e you are making your router as DHCP client) , then also your later method comes handy , as again you don't have to worry about the IP address , DHCP server will allocate "interface" keyword will take care of everything.

HTH...rate if helpful..