Mainframe Appliance for Networking Overview
Bus-Tech's
Mainframe Appliance for Networking ("Mainframe
Appliance") emulates an IBM 3172 TCP/IP controller. The Mainframe Appliance
uses industry-standard 8232 emulation supported by all mainframe TCP/IP systems,
such as IBM's TCP/IP for VM or MVS, Interlink's SNS/TCPaccess,
Connectivity System's TCP for VSE, and Barnard Software's TCP/IP- Tools.
It requires defining 2 host devices (as 3088 or CTCA devices) for each TCP link
to the mainframe. You may create multiple TCP links, thereby permitting you to
run test copies of your mainframe TCP/IP programs, without impacting the
production system.
The number of users
that can access the mainframe via the Mainframe Appliance is limited only by the
capacity of your network, the speed of the channel connection, and the capacity
of your mainframe TCP/IP software to handle TCP/IP connections and sessions.
There is no maximum limit of users or connections imposed by the Mainframe
Appliance itself.
Specifying the IP Address
With
its implementation of TCP/IP Passthru on the Mainframe Appliance, Bus-Tech
provides -- and recommends -- a way to specify the mainframe IP address in the
Mainframe Appliance software configuration, so that extraneous IP packets can be
filtered out at the Mainframe Appliance before they are forwarded to the
mainframe. This feature can remove a considerable amount of overhead on the
mainframe by blocking packets which are not relevant to the host.
Multiple
TCP links to the host may be created, serviced by a single LAN port in the
Mainframe Appliance. Each TCP link then has its own unique IP address specified
in a configuration table in the Mainframe Appliance TCP/IP Passthru software.
If you are
unfamiliar with IP addressing, or you wish to better understand subnetting and
subnet masks, please examine our tutorial on
IP addressing and
subnetting.
Preparing a Mainframe IOCP Definition
The mainframe I/O
configuration has to be updated to add your Mainframe Appliance TCP/IP
controller addresses. Click on the following links to review examples of an IOCP
configuration for the Mainframe Appliance for attachment to a
Bus-and-Tag-channel or to an
ESCON channel.
Updating the Mainframe TCP/IP
Configuration
The mainframe TCP/IP
software, such as IBM's TCP/IP for MVS, or Interlink's TCP-Access, has a
configuration file which must be updated to add your Mainframe Appliance TCP/IP
controller. Review examples of various TCP/IP
configurations which show how to define the Mainframe Appliance to various
Host TCP/IP programs..
If you are
unfamiliar with IP addressing, or you wish to better understand subnetting and
subnet masks, please examine our tutorial on IP
addressing and subnetting.
Configuring the
Mainframe Appliance using the RS-232 Serial Port
In rare situations
where a connection to the Mainframe Appliance via NetMeeting cannot be completed,
it may be necessary to configure the Mainframe Appliance using the RS-232 Serial
Port on the Mainframe Appliance. Bus-Tech has prepared a Technical Tip
that outlines the steps necessary to perform this function. Click the
following hyperlink to see How to Configure
the Mainframe Appliance using the Serial Port.
How To Run
Mainframe Operating System Traces
Bus-Tech Customer
Support may ask you to take traces of the mainframe device I/O, in the event
that it appears the Mainframe Appliance is having problems communicating with
the mainframe. We have prepared several examples for you to review if you are
unfamiliar with how to get mainframe traces. Select an example below based on the
type of operating system you are using:
How to update
the Channel Adapter Board Firmware
It may be
necessary on occasion to update the Channel Adapter Board firmware in your
Mainframe Appliance to a newer version.
Click here for a PDF file
containing complete step by step instructions for performing the update.
Note that it will be
necessary to take the MAN offline to the Mainframe during this update.
How to update
the Channel Adapter Drivers
It may be
necessary on occasion to update the Channel Adapter Drivers in your Mainframe
Appliance to a newer version.
Click here for a PDF file
containing complete step by step instructions for performing the update.
Note that it will be
necessary to take the MAN offline to the Mainframe during this update.
How to update
the TCP/IP Passthru Software
It may be
necessary on occasion to update the TCP/IP Passthru Software in your
Mainframe Appliance to a newer version.
Click here for a PDF file
containing complete step by step instructions for performing the update.
Note that it will be
necessary to take the MAN offline to the Mainframe during this update.
Common Mainframe
Appliance Set-up Problems
-
Error
"SIO CC 3" on the second device address
Ensure that you define 2 consecutive host addresses for each TCP/IP "3172"
link. The first device reads data from the Mainframe Appliance, and the second
device writes data to the Mainframe Appliance. If you are connecting the
Mainframe Appliance to a bus-and-tag channel interface, the TCP/IP "3172"
link is normally defined to IOCP as a control unit type of 3088, and a
unit type of CTC or 3088. If you are connecting to an ESCON channel, the
control unit type is SCTC.
-
Mainframe
cannot VARY ONLINE the two device addresses for a link
There are a variety of reasons why this might occur.
The Mainframe Appliance might not be fully powered up and online.
After the Mainframe
Appliance is booted, you will hear 4 "beeps" when the Mainframe
Appliance is ready to come online to your mainframe.
The device addresses for the link to the mainframe TCP/IP might not have
been specified, or they might not match the addresses specified in the mainframe TCP/IP
link configuration. Especially with ESCON devices, the device addresses used by
the mainframe might be e.g. 8A0 and 8A1, but the IOCP definition used the
keyword UNITADD=((00,2)) which means that the channel will identify those
devices as 00 and 01, instead of A0 and A1. The Mainframe Appliance device
address must match the UNITADD keyword values, and not the mainframe device
address values.
-
Mainframe
MVS TCP/IP application shows errors in allocating the two controller addresses
This problem is specific to MVS, and is typically caused by IBM's System Managed
Storage (SMS) interfering with the Mainframe Appliance controller addresses. SMS
may be set up to control all devices unless certain addresses are specifically
excluded. Symptoms typically include startup error messages such as these:
IKJ56880I FILE TCP0900 NOT ALLOCATED+
IKJ56880I UNIT AND VOLUME SPECIFIED ARE NOT SAME DEVICE TYPE
IGD01010I DATA GOING TO ( VIOSG ) STORAGE GROUP
EZB5300E LCS1: SetIoHand (Open) failed for device address 0900, Return Code=12
EZB4465E PCCA3 shutting down:
In
this case, the controller addresses of 900 (and 901) could not be dynamically
allocated by IBM's MVS TCP/IP because they were controlled by SMS. Once device
addresses 900 and 901 are excluded from SMS control, the Mainframe Appliance
controller can come online to MVS TCP/IP and start without problems.
-
Mainframe
is displaying I/O errors indicating Interface Control Checks
This is seen only on a bus-and-tag channel interface, and not ESCON.
When a channel adapter is getting Interface Control Check errors (the message
will indicate an I/O error on the virtual 3172 device address, with a unit
status of 02 or 0E, and a channel status of 02), the reason is often a channel
speed mismatch. It may be that the Mainframe Appliance has been configured to
run at 4.5MB streaming mode, but the Host IOCP definition indicates DCI or 3.0MB
mode, or perhaps the channel itself cannot support the configured speed. In most
cases, the mainframe IOCP is the source of the problem. When the Mainframe
Appliance is configured to run in DCI mode, it will run safely without errors (at
DCI speed) no matter what speed has been coded in the IOCP definition. However,
if the Mainframe Appliance is configured for a specific streaming speed and the
Host IOCP has been configured for DCI or a difference streaming speed, problems
will occur. Review your IOCP definition and ensure that the speed setting (PROTOCOL=)
is correct, and verify that the channel is capable of operating at the specified
streaming speed.
-
You
can vary on the 2 Mainframe Appliance addresses, but you cannot PING or
FTP or login via TELNET to the Host
IBM's TCP/IP for MVS or VM has an undocumented assumption about IP addresses:
All addresses between 1.x.x.x and 127.x.x.x are considered Class-A addresses.
All addresses between 128.x.x.x and 191.x.x.x are considered Class-B addresses.
All addresses between 192.x.x.x and 254.x.x.x are considered Class-C addresses.
If you switch from one address class to another without modifying
the IBM TCP/IP GATEWAY statement, the TCP/IP connection will not work.
Click here for more detailed
information, and examples on how to properly code the GATEWAY
statement.
-
The
Mainframe Appliance does not move traffic until a PING is sent out from
the mainframe
This problem often points to a routing problem in your network. When this
situation occurs, broadcasts appear to be suppressed in your network for some
reason. You should place a network traffic analyzer, such as a Sniffer from
Network General or the Microsoft Network Monitor, on your network to view LAN
packets when the Mainframe Appliance attempts to move traffic.
ANTI-VIRUS
INFORMATION
The
procedure to protect the MAN1100 and MAN1200 from the Blaster Worm virus
involves a three step process of installing the following Microsoft updates:
1. Windows NT 4.0
SP6a
2. Microsoft Security Rollup - Q299444i
3. (MS03-039) Patch for the Blaster.exe worm - KB824146
Bus-Tech
TECH NOTE 030905 provides
a step-by-step overview of the process. Left click to
view the PDF document. Right click to download it.
