-----------------------------------------------------------------
                    Hercules Networking
-----------------------------------------------------------------

    *** Please read herctcp.html as Roger explains how ***
    *** to set up TCP/IP networking with Hercules.     ***

All of the communications emulation implemented within Hercules
use a CTCA (Channel to Channel Adapter) type device. Depending on
the "flavor", the CTCA device will provide either a
point-to-point or a virtual network adapter interface to the
driving system's TCP/IP stack or in the case of CTCT, a "true"
CTCA connection to another instance of Hercules via a TCP/IP
connection.

All current emulations, with the exception of VMNET and CTCT use
the Universal TUN/TAP driver on *nix and TunTap32 (WinPCap) on
the Windows platforms which creates a network interface on the
driving system which allow Hercules to present frames to, and
receive frames from the TCP/IP stack. This network interface is
configured on *nix platforms by the hercifc program which is
invoked by Hercules after the TUN/TAP device is opened. The
hercifc program runs as root. Please read herctcp.html for more
information on the security implications of the hercifc program.

Now for the gory details:

---------------------------------------------------------------

    *** Important information about changes to the ***
    *** Hercules configuration files - PLEASE READ ***

The format of the Hercules configuration file statements for all
of the networking emulations have changed from the previous
releases of Hercules. The older format will still be accepted
to maintain compatibility, however it is the recommendation
of the maintainer that the new format be used. Also note that
there is no distinction between the CTCI and CTCI-W32 modes any
more, in fact CTCI-W32 does not exist in this release (other
than to maintain compatibility with previous configuration files).

---------------------------------------------------------------

    *** Important information about changes to the ***
    *** Hercules configuration files - PLEASE READ ***

In releases prior to Hercules version 3.00, all of the TCP/IP
emulations required two addresses to be defined in the Hercules
configuration file: one address for the read subchannel and the
other for write.

---------------------------------------------------------------

    *** Important information about changes to the ***
    *** Hercules configuration files - PLEASE READ ***

Hercules release version 3.00, however, [temporarily] changed
the rules: With [ONLY!] version 3.00 of Hercules, only the FIRST
address address need be specified in the configuration file.
Hercules version 3.00 automatically creates the second address.
Care must be taken to NOT define the second address [with Hercules
version 3.00 ONLY!] or a configuration error will occur.

---------------------------------------------------------------

    *** Important information about changes to the ***
    *** Hercules configuration files - PLEASE READ ***

Starting with Hercules version 3.01 however, we've gone back to
doing things the way we ORIGINALLY were (and the way most users
are used to (i.e. the way most users EXPECT things to work)):

With Hercules version 3.01 you need to define BOTH addresses!

Both the even numbered read device AS WELL AS the odd numbered
write device must BOTH be defined in your Hercules configuration
file starting with Hercules version 3.01. We apologize for the
mess, but we thought having Herc automatically define the write
device for you (as it does in version 3.00) would be easier for
everyone. Turns out it caused a lot of problems with a lot of
people, so we decided to go back to the original way. Again, we
apologize for whatever headaches this may have caused anyone.

---------------------------------------------------------------

    *** Important information about changes to the ***
    *** Hercules configuration files - PLEASE READ ***

Note that the VMNET and CTCT protocols have ALWAYS required BOTH
addresses to be defined (i.e. ALL versions of Hercules, including
version 3.00 as well, require BOTH even/odd read/write devices to
be defined separately [in your Hercules configuration file]).

---------------------------------------------------------------

The currently supported emulation modes are:

     CTCT     - CTCA Emulation via TCP connection
     CTCI     - Point-to-point connection to the host IP stack.
     LCS      - LAN Channel Station (3172/OSA)
     VMNET    - Point-to-point link via SLIP/VMNET

-----------------------------------------------------------------
CTCT - Channel to Channel Emulation via TCP connection
-----------------------------------------------------------------

This emulation mode provides protocol-independent communication
with another instance of this driver via a TCP connection.

This mode appears to the operating system running in the Hercules
machine as an IBM 3088 Channel to Channel Adapter and can operate
in either Basic or Extended mode.

The configuration statement for CTCT is as follows:

     <devnum> 3088 CTCT <lport> <raddress> <rport> <mtu>

where:

     <devnum>   is the address of the CTCT device.

     <lport>    is the TCP/IP port on the local system.

     <raddress> is the IP address on the remote.

     <rport>    is the TCP/IP port on the remote system.

-----------------------------------------------------------------
CTCI     - Channel to Channel link to Linux TCP/IP stack
-----------------------------------------------------------------

This is a point-to-point link to the driving system's TCP/IP
stack. From the point of view of the operating system running
in the Hercules machine it appears to be a CTC link to a machine
running TCP/IP for MVS or VM.

CTCI uses the Universal TUN/TAP driver on *nix and Politecnico
di Torino's WinPCap packet driver as well as Fish's TunTap32
and FishPack DLLs on Windows[1].

The configuration statement for CTCI is as follows:

     <devnum1-devnum2> CTCI [options] <guestip> <hostip>

where:

     <devnum1-devnum2>   is the address pair of the CTCI device.

     <guestip>  is the IP address of the Hercules (guest OS) side.

     <hostip>   is the IP address on the driving system.

     [options]  can be any of the following:

         -n <devname> or --dev <devname>

             where <devname> is:

             [*nix] the name of the TUN/TAP special character
             device, normally /dev/net/tun.

             [Windows] is either the IP or MAC address of the
             driving systems network card. TunTap32 will
             automatically select the first network card it
             finds if this option is omitted, this may not be
             desirable for some users.

         -t <mtu> or --mtu <mtu>

             [*nix only] where <mtu> is the maximum transmission
             unit size, normally 1500

         -s <netmask> or --netmask <netmask>

             [*nix only] where <netmask> is the netmask to
             be configured on the link. Note: Since this is a
             point-to-point link netmask is meaningless from
             the perspective of the actual network device.

         -m <MAC Address> or --mac <MAC address>

             [Windows only] where <MAC Address> is the optional
             hardware address of the interface in the format of
             either xx:xx:xx:xx:xx:xx or xx-xx-xx-xx-xx-xx.

         -k <kbuff> or --kbuff <kbuff>

             [Windows only] where <kbuff> is the size of the
             WinPCap kernel buffer size, normally 1024.

         -i <ibuff> or --ibuff <ibuff>

             [Windows only] where <ibuff> is the size of the
             WinPCap I/O buffer size, normally 64.

         -d or --debug

             this will turn on the internal debugging routines.
             Warning: This will produce a tremendous amount of
             output to the Hercules console. It is suggested that
             you only enable this at the request of the maintainers.

-----------------------------------------------------------------
LCS - LAN Channel Station
-----------------------------------------------------------------

This emulation mode appears to the operating system running in
the Hercules machine as an IBM 8232 LCS device, an IBM 2216
router, a 3172 running ICP (Interconnect Communications Program),
the LCS3172 driver of a P/390, or an IBM Open Systems Adapter.

Rather than a point-to-point link, this emulation creates a
virtual ethernet adapter through which the guest operating system
running in the Hercules machine can communicate. As such, this
mode is not limited to TCP/IP traffic, but in fact will handle
any ethernet frame.

The configuration statement for LCS is as follows:

     <devnum1-devnum2> LCS [options] [<guestip>]

where:

     <devnum1-devnum2>   is the address pair of the LCS device.
                This pair must be an even-odd address.

     [<guestip>] is an optional IP address of the Hercules
                (guest OS) side. Note: This is only used to
                establish a point-to-point routing table entry
                on driving system. If you use the --oat option,
                do not specify an address here.

There are no required parameters for the LCS emulation, however
there are several options that can be specified on the config
statement:

     -n <devname> or --dev <devname>

         where <devname> is:

         [*nix] the name of the TUN/TAP special character device,
         normally /dev/net/tun.

         [Windows] is either the IP or MAC address of the driving
         systems network card. TunTap32 will automatically select
         the first network card it finds if this option is
         omitted, this may not be desirable for some users.

     -o <filename> or --oat <filename>

         where <filename> specifies the filename of the Address
         Translation file. If this option is specified, the optional
         <guestip> and --mac entries are ignored in preference to
         statements in the OAT. (See below for the format of the OAT)

     -m <MAC Address> or --mac <MAC address>

         where <MAC Address> is the optional hardware address of
         the interface in the format: xx:xx:xx:xx:xx:xx

     -d or --debug

         this will turn on the internal debugging routines.
         Warning: This will produce a tremendous amount of
         output to the Hercules console. It is suggested that
         you only enable this at the request of the maintainers.


If no Address Translation file is specified, the emulation module
will create the following:

     An ethernet adapter (port 0) for TCP/IP traffic only.
     Two device addresses will be defined (devnum and devnum + 1).


The syntax for the Address Translation file is as follows:

*********************************************************
* Dev Mode Port Entry specific information              *
*********************************************************
  0400  IP   00  PRI 172.021.003.032
  0402  IP   00  SEC 172.021.003.033
  0404  IP   00  NO  172.021.003.038
  0406  IP   01  NO  172.021.002.016
  040E  SNA  00

  HWADD 00 02:00:FE:DF:00:42
  HWADD 01 02:00:FE:DF:00:43
  ROUTE 00 172.021.003.032 255.255.255.224

where:

     Dev   is the base device address
     Mode  is the operation mode - IP or SNA
     Port  is the virtual (relative) adapter number.

When the device is specifies the odd address of the pair,
then the read/write functions of the pair will be swapped.

For IP modes, the entry specific information is as follows:

     PRI|SEC|NO  specifies where a packet with an unknown IP
                 address is forwarded to. PRI is the primary
                 default entry, SEC specifies the entry to use
                 when the primary is not available, and NO
                 specifies that this is not a default entry.

     nnn.nnn.nnn.nnn specifies the home IP address

When the operation mode is IP, specify only the even (read)
address. The odd (write) address will be create automatically.

Note: SNA mode does not currently work.

Additionally, two other statements can be included in the
address translation file. The HWADD and ROUTE statements.

Use the HWADD to specify a hardware (MAC) address for a
virtual adapter. The first parameter after HWADD specifies
with relative adapter for which the address is applied.

The ROUTE statement is included for convenience. This allows the
hercifc program to create a network route for this specified
virtual adapter. Please note that it is not necessary to include
point-to-point routes for each IP address in the table. This is
done automatically by the emulation module.

Up to 4 virtual (relative) adapters 00-03 are currently supported.

-----------------------------------------------------------------
SLIP/VMNET  - Channel to Channel link to TCP/IP via SLIP/VMNET
-----------------------------------------------------------------

If the emulation mode is not specified on the configuration
statement, it is assumed to be a point-to-point link to the
driving system's TCP/IP stack using Willem Konynenberg's VMNET
package.  This provides the same function as the CTCI mode of
operation, except that it uses a virtual SLIP interface instead
of the TUN/TAP driver.

Refer to http://www.kiyoinc.com/herc3088.html for more details.



=================================================================
[1] The TunTap32.dll and FishPack.dll are part of Fish's CTCI-W32
http://www.softdevlabs.com/Hercules/ctci-w32-index.html
package, but the required WinPCap packet driver must be installed
separately from http://www.winpcap.org  See Fish's web page for
details.

ALSO NOTE that it is HIGHLY RECOMMENDED that you stick with using
only the current RELEASE version of WinPCap and NOT any type of
'alpha' OR 'beta' version! Alpha and Beta versions of WinPCap are
NOT SUPPORTED! Only official *release* version are supported!

When you visit the WinPCap download web page, you need need to
scroll down the page a bit to reach the OFFICIAL RELEASE VERSION
of WinPcap. They usually put their Beta versions at the top of the
page, and BETA versions ARE NOT SUPPORTED. *Please* scroll down
the page and use and official RELEASE version. Thanks.

You may, if you want, use a beta version of WinPCap, but if you do,
then you're on your own if you have any problems with it.

  -- Fish, May 2004.
