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Question on command for ip nat inside source

I have a Cisco 831 to be configured and there is a default command "ip nat inside source list 102 interface Ethernet1 overload".

Access-list 102 permit ip 10.10.10.0 0.0.0.255 any.

The router has a DHCP pool configured. The Ethernet1 has "ip nat outside" and "ip address dhcp client-id Ethernet1". It is the out of the box configuration.

I am trying to find documentation at CCO that explains it but I could not find anything good.

Can you help me on find it? Or can you explain that? Looks like all ip from Ethernet 1 will need pass throught NAT befor goes out and needs to macth the ACL 102.

Thanks,

Gilson

1 REPLY
Bronze

Re: Question on command for ip nat inside source

As written the command will nat all traffic from hosts with addresses 10.10.10.1-254 coming from an interface that has "ip nat inside" (is that on e0?) and going out the interface with "ip nat outside" (your e1). It will nat to the address of the e1 interface and overload using Port Address Translation so the everyone going out will have the same ip address as e1.

The DHCP pool is a different function from the nat. It is used to give hosts on the inside their inside addresses. It probably looks related because the pool uses the 10.10.10.x addresses that NAT identifies as the inside addresses. They are separate but must be coordinated like that for nat to work.

If you have one Internet address put it on the ethernet port. Everything will be nat'd to it.

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