Version 1.0: August 11, 1996 (cjm)

Version 1.1:  August 20, 1996  (cjm)
    - Host accepts incoming connections for ports 0 to 1023.

Version 1.2:  September 7, 1996 (cjm)
    - Fragment handling error in alias_db.c corrected.

Version 1.3:  September 15, 1996 (cjm)
    - Generalized mechanism for handling incoming
      connections (no more 0 to 1023 restriction).

    - Increased ICMP support (will handle traceroute now).

    - Improved TCP close connection logic.

Version 1.4: September 16, 1996 (cjm)

Version 1.5: September 17, 1996 (cjm)
    - Corrected error in handling incoming UDP packets
      with zero checksum.

Version 1.6: September 18, 1996
    - Simplified ICMP data storage.  Will now handle
      tracert from Win95 and NT as well as FreeBSD
      traceroute, which uses UDP packets to non-existent
      ports.

Version 1.7: January 9, 1997 (cjm)
    - Reduced malloc() activity for ICMP echo and
      timestamp requests.

    - Added handling for out-of-order IP fragments.

    - Switched to differential checksum computation
      for IP headers (TCP, UDP and ICMP checksums
      were already differential).

    - Accepts FTP data connections from other than
      port 20.  This allows one ftp connections
      from two hosts which are both running packet
      aliasing.

    - Checksum error on FTP transfers.  Problem
      in code located by Martin Renters and
      Brian Somers.

Version 1.8: January 14, 1997 (cjm)
    - Fixed data type error in function StartPoint()
      in alias_db.c (this bug did not exist before v1.7)
      Problem in code located by Ari Suutari.

Version 1.9: February 1, 1997 (Eivind Eklund <perhaps@yes.no>)
    - Added support for IRC DCC (ee)

    - Changed the aliasing routines to use ANSI style
      throughout (ee)

    - Minor API changes for integration with other
      programs than PPP (ee)

    - Fixed minor security hole in alias_ftp.c for
      other applications of the aliasing software.
      Hole could _not_ manifest in ppp+pktAlias, but
      could potentially manifest in other applications
      of the aliasing. (ee)

    - Connections initiated from packet aliasing
      host machine will not have their port number
      aliased unless it conflicts with an aliasing
      port already being used. (There is an option
      to disable this for debugging) (cjm)

    - Sockets will be allocated in cases where
      there might be port interference with the
      host machine.  This can be disabled in cases
      where the ppp host will be acting purely as a
      masquerading router and not generate any
      traffic of its own.
      (cjm)

Version 2.0: March, 1997 (cjm)
    - Aliasing links are cleared only when a host interface address
      changes.

    - PacketAliasPermanentLink() API added.

    - Option for only aliasing private, unregistered
      IP addresses added.

    - Substantial rework to the aliasing lookup engine.

Version 2.1: May, 1997 (cjm)
    - Continuing rework to the aliasing lookup engine
      to support multiple incoming addresses and static
      NAT.  PacketAliasRedirectPort() and
      PacketAliasRedirectAddr() added to API.

    - Now supports outgoing as well as incoming ICMP
      error messages.

Version 2.2: July, 1997 (cjm)
    - Rationalized API function names to all begin with
      "PacketAlias..."  Old function names are retained
      for backwards compatibility.

    - Packet aliasing engine will now free memory of
      fragments which are never resolved after a timeout
      period.  Once a fragment is resolved, it becomes
      the users responsibility to free the memory.

Version 2.3: August 11, 1997 (cjm)
    - Problem associated with socket file descriptor
      accumulation in alias_db.c corrected.  The sockets
      had to be closed when a binding failed.  Problem 
      in code located by Gordon Burditt.

Version 2.4: September 1, 1997 (cjm)
    - PKT_ALIAS_UNREGISTERED_ONLY option repaired.
      This part of the code was incorrectly re-implemented
      in version 2.1.

Version 2.5: December, 1997 (ee)
    - Added PKT_ALIAS_PUNCH_FW mode for firewall
      bypass of FTP/IRC DCC data connections.  Also added
      improved TCP connection monitoring.

Version 2.6: May, 1998 (amurai)
    - Added supporting routine for NetBios over TCP/IP.

Version 3.0: January 1, 1999
    - Transparent proxying support added.
    - PPTP redirecting support added based on patches
      contributed by Dru Nelson <dnelson@redwoodsoft.com>.

Version 3.1: May, 2000 (Erik Salander, erik@whistle.com)
    - Added support to alias 227 replies, allows aliasing for
      FTP servers in passive mode.
    - Added support for PPTP aliasing.

Version 3.2: July, 2000 (Erik Salander, erik@whistle.com and 
      Junichi Satoh, junichi@junichi.org)
    - Added support for streaming media (RTSP and PNA) aliasing.

Version 3.3: May 2021 (donner)
    - Dropped LibAliasCheckNewLink
    - Refactor the database handling
    - Switch to more effienct SPLAY trees