*BSD News Article 86337


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From: Charles Mott <cmott@srv.net>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: "Masquerading is Evil", part 3
Date: Thu, 9 Jan 1997 23:19:44 -0800
Organization: Island Internet Inc. - (604) 753-2383
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I have completed a number of structural modifications 
to the packet aliasing (masquerading) software for user
mode ppp.  Version 1.7 can be found at:

    http://www.srv.net/~cmott/alias.html

Bug Fixes:

(1) The software now handles out-of-order fragments.
This doesn't affect too many people, butat least one
expert thought it was important to do.  To verify
this, try pinging an external linux machine (which
fragments backwards) from a computer behind the ppp
host on your LAN.  The example I use is:

    ping -s 5000 nanaimo.island.net

A large packet has to be used in order to cause
fragmenting.

(2) It was not formerly possible to make an FTP
data transfer between two machines which were both
running the packet aliasing software.  This was
because of an overly restrictive condition that 
FTP transfers must originate from port 20.

(3) An obsure IP checksum bug was isolated by Brian
Somers and Martin Renters.  This has been fixed.