Static/dynamic NAT and a pool of dynamic/dhcp external addresses?

From: Ralf Strandell (ralf.strandell_at_pp.inet.fi)
Date: 09/14/03 

Date: Sun, 14 Sep 2003 10:55:54 GMT

Hello

I'm planning to connect a LAN to the Internet. Thus I need to know a few
things about how NAT (not PAT) and DHCP work together.

Let's assume that I am using static private IP addresses on my LAN and that
my ISP's DHCP server provides on demand a pool of up to five public dynamic
IP addresses. Next I would connect my LAN to the Internet using a bridged
ADSL line.

If I now put a firewall between my LAN and the ADSL modem, then the
external interface of the firewall gets a dynamic public address from the
ISP's DHCP server.

I could use PAT to connect the networks, but not all protocolls work with
it, rigt? At least many multimedia / IP-phone etc. protocols requiring
multiple return ports would probably fail.

Now the questions...

- Static or dynamic NAT could be used to solve that problem, right?

- But are firewall appliances in general able to bind several dynamic/DHCP
addresses to the same external interface and then use that pool for static
or dynamic source NAT?

Relevant Pages

  • Re: Static/dynamic NAT and a pool of dynamic/dhcp external addresses?
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