RE: tlug: More IP addresses

[Scott Stone <sstone@example.com>]

On Wed, 9 Dec 1998, Uva Coder wrote:

> On Date: Tue, 8 Dec Renaud wrote:
> 
> >I need more IP addresses than I have.
> >
> >Masquerading sounds good to me, but someone told me that running a Proxy
> >server would do the "same". Is that true? I couldn't figure this out in the
> >documentation.
> 
> Yes, in theory they can, but I have not seen any proxy servers that do the
> equivalent to IP masquerading. IP masquerading is generally mimicked with
> firewall software and dhcp or a
> proxy server software and dhcp in the private sector.
> 
> The major difference with IP Masquerading and proxy servers in general is as
> follows:
> 
> IP masquerading translates IP addresses only. If a client computer on a
> intranet goes through a
> masquerading machine, the client`s IP packets are restamped at the
> masqeurading computer then
> sent to the internet. Additionally, if the masquerading machine has all
> services (inetd) turned off, the client will still be able to connect to the
> internet.
> 
> Proxy servers translate tcp or udp services on behalf of a client computer
> or network. The client`s IP packets are relayed to the proxy server`s own
> services. So if services in the inetd.conf are disabled in the proxy server,
> the client will not be able to connect to the internet.
> 
> I would recommend ip masquerading over a proxy server with dhcp. IP
> masquerading is quicker.

You can, however, use ipfwadm/ipchains on the masquerade server to limit
which services are accessible from the masqueraded clients.  I did this
here at PHT to prevent people from exporting their X displays through the
masquerade gateway :)

--------------------------------------------------
Scott M. Stone <sstone@example.com, sstone@example.com>
Head of TurboLinux Development/Systems Administrator
Pacific HiTech, Inc (USA) / Pacific HiTech, KK (Japan)


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