Conference help::decnet-osi_for_vms

3972.0. "DmQ,TCP/IP,Dual-Rail Ether,DECnet-PLUS?" by TKOV60::MORIG () Sat May 24 1997 04:02

Hello,

I'm trying to confirm the fail-over capability using DECmessageQ on TCP/IP.
Requirements are  as follows;
	(0) Fail-Over
	(1) TCP/IP
	(2) DECmessageQ
	(3) OpenVMS
	(4) Dual Rail Ethernet(FDDI) Switch Over (without user intervention)

Followings are previous conversation with DMQ engineering, and VMS 
engineering. They told in this note conference regarding the DECnet-Plus
with TCP/IP.

Someone can make clear the fail-over capability on the dual rail ethernet
with TCP/IP (DECnet-Plus) ?

Best regards,
Yukio

           <<< BULEAN::BULEAN$USER:[NOTES$LIBRARY]DECNETVAX.NOTE;1 >>>
                           -< DECnet-VAX Conference >-
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���� 5874.4         Multi-circuit end-node on dual rail.                 4 / 5
TKOV60::MORIG                                            33 �� 17-MAY-1997 01:13
                    -< DECnet-Plus on TCP/IP (Dual Rails) >-
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>    <<< XDELTA::HOFFMAN "Steve, OpenVMS Engineering" �ˤ��Ρ��� 5874.1 >>>
>                  -< DECnet Routing; "Prior Version" Support >-
>
>
>   DECnet phase IV routers and DECnet-Plus end-nodes do automatically
>   fail-over among available (working) circuits, and the fail-over
>   process requires no manual intervention.
>
>   DECnet-Plus also transparently supports multiple Ethernet rails, and
>   multiple Ethernet controllers connected to the same Ethernet rail.
>

We are trying to resolve our customer requirement.
They are using dual rail ethernet with FDDI on OpenVMS v6.2 and DECnet/OSI 
v6.3.

They are trying to change the protocol from DECnet to TCP/IP.

They understand that UCX can't handle dual homing IP nor Path Splitting on
the dual rail.

I heard DECnet-plus works on UCX for TCP/IP stack.

Do you mean they can use TCP/IP with dual rail and automatic fail over?

If possible, we want to use DECmessageQ on TCPIP with DECnet-Plus.
I asked about the dual homing IP support at DMQ note conference, but DMQ
didn't support it.......

Please let me know.

Best regards,
Yukio Moriguchi

         <<< PAMSRC::SYS$SYSDEVICE:[NOTES$LIBRARY]DECMESSAGEQ.NOTE;1 >>>
                          -< NAS Message Queuing Bus >-
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�Ρ��� 2881.0            Fail over - Dual rail Ethernet         ��ץ饤�ο�� 4
TKOV60::MORIG                                            38 �� 16-MAY-1997 07:52
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I want to know whether I can create fail safe network configuration using
DECmessageQ over TCP/IP.

Can DMQ switch from a line-a to a line-b without any operation, when 
a line-a goes down ?

Can DMQ use both lines simultaneously ?

Can DMQ swith TCP/IP to DECnet ?

+---------------------+			+---------------------+
|    OpenVMS 6.2      |                 |     OpenVMS 6.2     |
|       UCX  4.0      |                 |        UCX  4.0     |
|       DMQ  3.2      |                 |        DMQ  3.2     |
|                     |                 |                     |
|    1a         1b    |                 |   2b          2a    |
| +------+   +------+ |                 | +-----+    +------+ |
| |ether |   |ether | |                 | |ether|    |ether | |
+-+------+---+------+-+                 +-+-----+----+------+-+
     |          |            line b           |          |
     |      []====================================[]     |
     |                       line a                      |
[]================================================================[]



DMQ$INIT.TXT

	GroupID	 System	      .....	Transport    Addr
	-------  -------		---------   ------
	  1	   1a			   TCPIP     xxx1
	  1	   1b			   TCPIP     xxx1
	  2	   2a			   TCPIP     xxx1
	  2	   2b			   TCPIP     xxx1
		

Regards,
Yukio Moriguchi
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���� 2881.1            Fail over - Dual rail Ethernet                    1 / 4
PAMSIC::STEPHENS                                         26 �� 16-MAY-1997 12:25
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Hello,

>Can DMQ switch from a line-a to a line-b without any operation, when 
>a line-a goes down ?

No, the product does not support dual-homed IP configurations such
as you described in .0

>Can DMQ use both lines simultaneously ?

No, except, if these systems are on the same LAN, and if your
application is so inclined, then you can use the SBS server which
is setup to broadcast on dual rail configurations (using direct
multicasting, not TCP/IP)

>Can DMQ swith TCP/IP to DECnet ?

Yes, the transport control can switch between link drivers 
(DECnet and TCP/IP), however this would be a major managment
headache, if you were suggesting to run DECnet over one rail
and IP on the other.    

Hope this helps,
Bruce

Bruce
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���� 2881.2            Fail over - Dual rail Ethernet                    2 / 4
KLOVIA::MICHELSEN "BEA/DEC MessageQ Engineering"         14 �� 18-MAY-1997 22:35
                             -< This may help... >-
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    re: .0
    
>Can DMQ switch from a line-a to a line-b without any operation, when 
>a line-a goes down ?

>Can DMQ use both lines simultaneously ?

>Can DMQ swith TCP/IP to DECnet ?
    
    BTW, DECnet supports dual-rail ethernet transparently, all you have to
    do is make sure it's enabled.
    
    
    Marty
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���� 2881.3            Fail over - Dual rail Ethernet                    3 / 4
TKOV60::MORIG                                            13 �� 19-MAY-1997 08:00
                                  -< Really? >-
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BEA/DEC messageQ on Digital UNIX can swith the dual rails Ethernet.

DECnet-Plus can use dual rails transparently and with fail-safe. 

Only on OpenVMS with UCX CAN't handle it?

If we use DECnet-Plus on TCP/IP, though it is the UCX, can we use dual rails
on TCP/IP with the messageQ?

We need dual rails support on TCP/IP, DMQ with MRS.

Regards,
Yukio
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���� 2881.4            Fail over - Dual rail Ethernet                    4 / 4
KLOVIA::MICHELSEN "BEA/DEC MessageQ Engineering"          6 �� 23-MAY-1997 14:01
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re: .3

I am not familar with those capabilities of DECnet-Plus.


Marty

Yukio,

If you use DECnet-Plus over TCP/IP then you are stuck with the capabilities
of TCP/IP !!!

Of course, if you application can do application level fail-over then the
application is allowed to do that. In this case your "application" is DMQ. If
it has some way to connect to "fred" and if "fred" fails then connect to
"jim" transparently, then there may be some way for DMQ to achieve what you
want ... But, as I don't know DMQ, I'll ignore that possibility.

The rules of TCP/IP are that:

	a) each interface has an address (not each node, as in DECnet)

	b) each "datalink" (eg LAN) has its own subnet

	c) The address of an interface on LAN-A will consist of the
	   subnet address of LAN-A with a "host" number (identifying the
	   interface) appended. Thus, an interface address might be "host" 3
	   on "subnet" 1.2.3, and that would give an address of 1.2.3.3

	d) IP will always use what it considers to be the shortest path, so
	   the shortest paths to all addresses starting 1.2.3 will be via the
	   interface whose address starts 1.2.3. Furthermore, all other
	   LANs on the same node will start with something other than 1.2.3

From the above, you will see that if you have LAN-A and LAN-B then they will
be different subnets. When you use TCP/IP (or DECnet-Plus over TCP) you will
have to choose a name, and the name will translate to an address, which
will define which subnet you are connecting to. If the subnet is directly
connected (ie a directly connected LAN) then you will have also chosen the
path to use -- in other words if you choose the remote LAN-A connected address
then you will be using LAN-A and if you choose the remote LAN-B connected
address you will be using LAN-B. If your chosen LAN fails then the connection
will drop.

ie no automatic fail-over when using TCP/IP -- and therefore when using
DECnet-Plus over TCP/IP

Regards,

	John

Thank you John.

I appreciate your clear reply.

Can I use cluster alias for that purpose in a node?

Regards,
Yukio

Nope, the cluster alias in IP is a gross kludge and a hack that operates
by moving the IP address from one interface on a IP net to another IP address
on the same IP net and then ARPing to cause the other nodes to update their
IP address to Ethernet address translation table.

To make what you want to work requires a real routing layer.

One solution would be to implement OSPF or I-IS-IS on the host nodes and
then create a virtual interface which would be the node IP address and the
use path splitting to either provide fault tolerance or scalable bandwidth.
Gag me with a spoon.

By the way, take a good look at the IPng work and you will not find any
real acceptance of a requirement that matches yours.  Not that it hasn't
been put forth.  Basically, the solution to this is considered something
that requires significant research.  Any work done by ISO doesn't count because
you can't access the specs over the internet so what DECnet-PLUS offers doesn't
really exist.