DECNET network switch over in event of network failure

[Robert_Boyd]

Colin,

What if some of the nodes involved in the network are still running on VMS V5.x(or earlier) with DECnet extensions? Will those systems also continue to work properly on the remaining interfaces?

I can believe that with DECnet-Plus systems in the V7.x and later range that your description is accurate, but I am pretty sure that earlier versions may not handle it all so gracefully.

Robert

[eran_6]

Thanks everybody for the assistance.

We understood that, for DECNET Phase V, one can provide fail over out of the box. However, because in DECNET Phase IV, an Alpha DECNET node can not be a router and can not be an owner of more than one line/circuit, failover is not as simple.

As Colin mentioned, for IP there's a procedure known as "failsafe IP". We didn't check it out yet.

In any case, we've decided (for now) to try to use the Lan fail over method as mentioned by Andy (System Manager's Manual vol 2 chapter 10).

[Volker Halle]

Visa,

LAN failover (according to the manual):

'is a mechanism for protecting your system from a LAN device failure'

Both (all) LAN devices in a LAN failover set must be connected to the SAME EXTENDED LAN.

LAN failover protects you from a failure in a LAN device, cable or switch. Nothing more. LLDRIVER just acts on the Link up/Link down transitions.

Volker.

[Robert_Boyd]

visa,

What are the versions of VMS and DECnet that you're running?

NCP SHOW EXEC CHAR and
NCL SHOW IMPLEMENTATION

are the commands to get the relevant info.

It might be helpful to some of us to see the various versions that you have to contend with.

Probably best to remove/obfuscate the node names as that is not essential to the discussion.

Robert

[Colin Butcher]

Robert,

Actually DECnet/OSI V6.3 (back in VAX VMS V5.5-2 days) would do this stuff - once a lot of the implementation details and some of the design assumptions were fixed (things like probe rate). You might remember a load of ECOs coming out in quick succession. Those fixed a lot of the dual-LAN failover and load balancing issues I found during testing. Biggest problem I had back then was working out how to implement DECdns failover. Got it sorted in the end.

Ah well.

Cheers, Colin.