Re: [TCLUG:3635] Hub and IP question

[Michael Hicks <hick0088@tc.umn.edu>]

> Thanks for the advice.  I have some more questions, though.
> 
> 1.  Does the proxy machine need two ethernet cards?  A Web site I found
> (http://www.jrd.com/masquerading.html) makes it sound like the system that
> handles the masquerading needs to have two cards, with the hub on one card
> and the outside network on the other.  Is this the case?

Well, I'll start _my_ answer with a big disclaimer: _IN_THEORY_, you
should be able to do it with only one network card.  This involves
setting up the ethernet card to have multiple IP addresses (I think this
is also termed "Virtual Hosting" in some instances).  There's an option
that has to be enabled in the kernel to do that.  I'm not sure if IP
Masq works terribly well with these 'virtual' devices, though.

> 2.  Will the speed of the proxy machine have a major impact on the speed of
> the network?  Will it make a difference if I have a 486/33 vs. a 486/50 as
> the "gateway"?  Or should I really have it all run through the Pentium 166
> system?  My plan was to run one of the 486's only as the proxy, but how
> will that compare to the P166 (which would not be a dedicated system)?

I would definitely put the faster 486 as the proxy (but that's just
me).  If you try to do the single ethernet card trick, your theoretical
maximum will be 5 Megabit, since the same card has to do sending and
receiving.  Of course, you'd probably have an ISA card in the 486, so
there would be more overhead, and not all of the bandwidth would be
available to you.  I'd still expect you to at least manage 3 Megabit,
which I'm sure you can live with ;-)  Needless to say, if you put two
ethernet cards in the proxy box, you should be able to get more of the
bandwidth available to you, but probably maxing out around 7 Megabit..
 
Pretty much, you won't notice for off-campus data transfer, since that
usually maxes out around 3-4 Megabit.  You may notice ftp.cs.umn.edu is
a little more sluggish, but maybe not.  Also, you won't be able to do
those cool 1 Megabyte/s transfers to your buddy next door anymore..  (oh
darn ;-)

> As always, I appreciate any help or wisdom yau can give me.

I hope I was moderately helpful..
-- 
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|               Mike Hicks | Linux User Since: 1.2.13
: http://umn.edu/~hick0088 | mailto:hick0088@tc.umn.edu
`              icq:6883760 | Current Kernel: 2.2.0-final