NAT questions...

rjbarlow

Hi all, i need yours advice for NAT.



Well, ISP 1 has given the network 165.34.72.0/24 to a private company with PC1 (at the left of the image). In this condition, I don't succeed to understand if with NAT I can to map the IP address of PC1 to the IP address of the s0/0 of router1 (that is 165.34.32.1) or this address is not possible to be used for natting or it's the only IP address I can use. The doubt comes from the fact that others IP addresses do not exist in the network 165.34.72.0 other than 1 and 2, therefore I'm not sure if router1 of the company process the packet with Dest. Addr. different from the IP address of his interface s0/0 and then forward the packet into network 192.168.1.0; normally it will discard.

However I have some difficulty to recognize the Outside Global address,
inside local is 192.168.1.1,
inside global is 165.34.72.x(?)
outside local is 148.24.50.16,
but i really don't match the outside global. Please if You have a comprehensible explanation give it to me.

Thanks in advance.

mwgood

I'll pass on the outside global address, but here are two options for NATing.

ip nat inside source list 1 interface Serial0/0 overload
access-list 1 permit 192.168.1.0 0.0.0.255


Another option:

ip nat inside source static 192.168.1.1 165.34.72.9 extendable

Cucumber

I don't think you need to do the outside local/outside global thing; you only need that in two scenarios.

First, if you wanted to connect two remote networks having the same RFC 1918 addressing:
192.168.1.0/24---R1---ISPR2---Internet---ISPR3---R4---192.168.1.0/24
or just
192.168.1.0/24---R1--192.168.1.0/24

Second, when you are not complying with the RFC 1918 private addressing because you are using a plublic "registered" network that was not assigned by the ISP on your private network, i.e.
1.0.0.0/8

---

R1----ISPR2---Internet

By the way, if that IP address "148.24.50.16" was assigned by the ISP2, and that host is the server you want to access from 192.168.1.1, all you need is the configuration already given by mwgood.

rjbarlow

OK guys, thanks to both!