Using NAT and several public IP on the same ethernet interface

Hello

I'm a network administrator and I need some advice.

I have a small network with a Cisco 2516 router, several servers and
lots of hosts. I also have a small range of public IP. I can't give a
public IP to every host, because I don't have enough. So, the question
is How can I organize the network?

I have thought two possibilities:

A: Using NAT for servers and hosts. Static NAT for Servers, and
NAT-PAT for hosts. This can improve network security, but the servers
need to use multimedia, and I don't know if there could be some
problems with NAT and ports. In this case, I will use an Ethernet
inteface as usual.

B: Configure two subinterfaces on Ethernet interface, with two
different addresses. Host will use private address and router will do
NAT . The other address will be public and the servers will have
public addresses. Do you know if this could be possible?

Which one could be possible or better?

Thanks in advance

Curro

 

Hi Curro.

I have a similar setup at one of my buildings. I have a public ip
range behind my firewall consisting of 14 usable ip addresses. I have
4 servers, each of them are statically bound to their own public ip
address. I have around 100 or so hosts that share the other ips via
NAT/PAT. My servers run many different services (web, imap, pop, ftp,
mysql) and they have no problem accomplishing the mission. Option A
would work good for you.

Good luck,

!Brian

 

| B: Configure two subinterfaces on Ethernet interface, with two
| different addresses. Host will use private address and router will do
| NAT . The other address will be public and the servers will have
| public addresses. Do you know if this could be possible?

I've done this by simply adding a secondary address on the interface.
Unless you are trying to create separate VLANs it isn't clear to me
that you would want to (or even could in many cases) use subinterfaces.

Dan Lanciani
[email protected]*com