Problem with IP addresses
george at galis.org
Fri Jun 2 22:47:38 PDT 2000
>Now, the problem:
>In the example with sendmail, above, it was not a big problem
>that pearce's sendmail considered pickering's IP address to
>the one for its eth2 interface rather than eth1's. However,
>what happens when pickering tries to, for example, query CTS'
>name server? It sends a packet to port 53 on NS.CTS.COM with a
>source address of 192.168.20.2, which, being private, gets
>pitched into the bit bucket by the firewall.
>If pickering were somehow made to put 184.108.40.206 as its
>source address in all the packets it sends anywhere, I should
>think that would do what I need to do. I can't think of any
>situation where a packet that originates with pickering could
>not be addressed with ...66, regardless of which of its three
>interfaces actually transports it.
>Well, I hope this hasn't gotten quite to the point of
>intolerability. I'll bet there's some simple answer, but I
>haven't quite found it yet.
I'll have a closer look tomorrow, but I would throw a 100mhz linux
router/firewall on the dsl connection and set it up for masq, ip alias it
and open routes for the static cloud IPs on your LAN, run sendmail on the
masq box and let it be a mail hub or a smarthost depending on which lan box
needs it. the masq should take care of the NS problem above.
I've given this situation some thought before but from a different
perspective. How do you balance a LAN on two DSL lines? (for fault
The trick is you don't want to be part of the clouds WAN but the problem
is you need root on both your ISPs to parallelize your two legs of the
internet. I've never done this but that seems to be the problem.
It would also be good to know (I'm sure) all those networking kernel system
calls too... But have you used MASQ?
Almost forgot, I'd use qmail not sendmail! I got it compiled and I think
it should be working it comes up in the ps tree, but since there were no
startup messages in the logs, I haven't begun to test it.
GEORGE GEORGALIS . ICXC . 858.621.9488
george at galis.org . . NIKI . . PO Box 3342
http://galis.org/george . . La Jolla, CA 92038
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